Java学习者

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<ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> CPU 飙升是一个常见的问题。 在生产环境中，会出现由代码问题导致CPU占用很高，该如何诊断出是哪行java代码导致? 是大家的一项重要基本功，也是大家面试中的家常骗饭。 如果连CPU 飙升的问题都回答不清楚，都支支吾吾，面试就很难通过了。 <h2 style="font-size: 24px;line-height: 32px;margin: 21px 0 5px 0;text-align: justify;">CPU100%定位的两大神器</h2> <section style="text-align: center;" nodeleaf=""> <img src="/upload/903f446eba9d0876b7f19b512145ee69.png" class="rich_pages wxw-img" data-ratio="0.33505154639175255" data-s="300,640" data-type="png" data-w="970" type="block" data-imgfileid="100000563"> </section> <h2 style="font-size: 24px;line-height: 32px;margin: 21px 0 5px 0;text-align: justify;">想要定位到具体是哪一行的代码导致，一般都会使用下面的两大神器</h2> <ul style="margin: 0;padding-left: 23px;" class="list-paddingleft-1"> <li>通常使用的jvm自带的工具jstack，</li> <li>还有一种就是开源神器arthas，</li> </ul> 一般而言，arthas还有其它的功能，所以选择它多一点. <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u349af361%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%7D%2C%22data%22%3A%22CPU%20%E9%A3%99%E5%8D%87100%25%E7%9A%84%E8%A7%A3%E5%86%B3%E6%80%9D%E8%B7%AF%22%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> CPU 飙升100%的解决思路与方法论 <section style="text-align: center;" nodeleaf=""> <img src="/upload/f47c9040269ca45d30d1bc86313bb243.png" class="rich_pages wxw-img" data-ratio="0.3001027749229188" data-s="300,640" data-type="png" data-w="973" type="block" data-imgfileid="100000550"> </section> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <h2 style="font-size: 24px;line-height: 32px;margin: 21px 0 5px 0;text-align: justify;">使用jstack 解决CPU 100%问题实操</h2> 使用jstack 解决CPU 100%问题，在方法论上要用到两个命令， <ul style="margin: 0;padding-left: 23px;" class="list-paddingleft-1"> <li>top 命令查看TOP N线程，</li> <li>jstack命令查看堆栈信息</li> </ul> <section style="text-align: center;" nodeleaf=""> <img src="/upload/e5cef8ab4cf8da21d44bd7f99cd2b844.png" class="rich_pages wxw-img" data-ratio="0.19328703703703703" data-s="300,640" data-type="png" data-w="864" type="block" data-imgfileid="100000551"> </section> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <h3 style="font-size: 20;line-height: 28px;margin: 16px 0 5px 0;text-align: justify;">1.jstack命令讲解</h3> 命令jstack是java堆栈的跟踪工具，可以打印出程序中所有线程的堆栈信息，包括线程状态，调用栈信息，锁信息等。 jstack可以诊断线程死锁、内存泄漏等问题 命令格式: jstack [options] pid 常用例子: jstack -l pid，查看线程的堆栈信息 堆栈信息解读: <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="sql"><code>[root@192-168-65-185 ~]# jstack -l 29440</code><code>2024-12-17 13:48:51</code><code>Full thread dump OpenJDK 64-Bit Server VM (25.412-b08 mixed mode):</code><code> </code><code>"Attach Listener" #12 daemon prio=9 os_prio=0 tid=0x00007f097c001000 nid=0x763a runnable [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"DestroyJavaVM" #11 prio=5 os_prio=0 tid=0x00007f09e004b800 nid=0x7301 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"pool-1-thread-1" #10 prio=5 os_prio=0 tid=0x00007f09e0166000 nid=0x7316 runnable [0x00007f09cc9cb000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> at com.tuling.learnjuc.demo.JVMCPU$CPUTask.run(JVMCPU.java:16)</code><code> - locked <0x0000000757d645b8> (a java.lang.Object)</code><code> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)</code><code> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)</code><code> at java.lang.Thread.run(Thread.java:750)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - <0x0000000757d65d00> (a java.util.concurrent.ThreadPoolExecutor$Worker)</code><code> </code><code>"Service Thread" #9 daemon prio=9 os_prio=0 tid=0x00007f09e0140000 nid=0x7314 runnable [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C1 CompilerThread3" #8 daemon prio=9 os_prio=0 tid=0x00007f09e0133000 nid=0x7313 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread2" #7 daemon prio=9 os_prio=0 tid=0x00007f09e0131000 nid=0x7312 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread1" #6 daemon prio=9 os_prio=0 tid=0x00007f09e012f000 nid=0x7311 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread0" #5 daemon prio=9 os_prio=0 tid=0x00007f09e012c800 nid=0x7310 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Signal Dispatcher" #4 daemon prio=9 os_prio=0 tid=0x00007f09e011e000 nid=0x730f runnable [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Finalizer" #3 daemon prio=8 os_prio=0 tid=0x00007f09e00f2000 nid=0x730e in Object.wait() [0x00007f09cd1d3000]</code><code>   java.lang.Thread.State: WAITING (on object monitor)</code><code> at java.lang.Object.wait(Native Method)</code><code> - waiting on <0x0000000757d08f00> (a java.lang.ref.ReferenceQueue$Lock)</code><code> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)</code><code> - locked <0x0000000757d08f00> (a java.lang.ref.ReferenceQueue$Lock)</code><code> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:165)</code><code> at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:188)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Reference Handler" #2 daemon prio=10 os_prio=0 tid=0x00007f09e00ed000 nid=0x730d in Object.wait() [0x00007f09cd2d4000]</code><code>   java.lang.Thread.State: WAITING (on object monitor)</code><code> at java.lang.Object.wait(Native Method)</code><code> - waiting on <0x0000000757d06b98> (a java.lang.ref.Reference$Lock)</code><code> at java.lang.Object.wait(Object.java:502)</code><code> at java.lang.ref.Reference.tryHandlePending(Reference.java:191)</code><code> - locked <0x0000000757d06b98> (a java.lang.ref.Reference$Lock)</code><code> at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"VM Thread" os_prio=0 tid=0x00007f09e00e3800 nid=0x730c runnable </code><code> </code><code>"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007f09e005e000 nid=0x7302 runnable </code><code> </code><code>"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007f09e0060000 nid=0x7303 runnable </code><code> </code><code>"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x00007f09e0062000 nid=0x7304 runnable </code><code> </code><code>"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x00007f09e0064000 nid=0x7305 runnable </code><code> </code><code>"GC task thread#4 (ParallelGC)" os_prio=0 tid=0x00007f09e0065800 nid=0x7306 runnable </code><code> </code><code>"GC task thread#5 (ParallelGC)" os_prio=0 tid=0x00007f09e0067800 nid=0x7307 runnable </code><code> </code><code>"GC task thread#6 (ParallelGC)" os_prio=0 tid=0x00007f09e0069800 nid=0x7308 runnable </code><code> </code><code>"GC task thread#7 (ParallelGC)" os_prio=0 tid=0x00007f09e006b800 nid=0x7309 runnable </code><code> </code><code>"GC task thread#8 (ParallelGC)" os_prio=0 tid=0x00007f09e006d000 nid=0x730a runnable </code><code> </code><code>"GC task thread#9 (ParallelGC)" os_prio=0 tid=0x00007f09e006f000 nid=0x730b runnable </code><code> </code><code>"VM Periodic Task Thread" os_prio=0 tid=0x00007f09e0142800 nid=0x7315 waiting on condition </code><code> </code><code>JNI global references: 5</code><code> </code></pre> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22uf892165a%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ua64d9cd3%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BD%A0%E4%BC%9A%E5%8F%91%E7%8E%B0%E4%B8%8A%E9%9D%A2%E7%9A%84%E4%BF%A1%E6%81%AF%E5%85%B6%E5%AE%9E%E6%98%AF%E4%B8%80%E6%AE%B5%E4%B8%80%E6%AE%B5%E7%9A%84%EF%BC%8C%E6%91%98%E5%8F%96%E5%85%B6%E4%B8%AD%E7%9A%84%E4%B8%80%E6%AE%B5%E4%B8%BA%E5%A4%A7%E5%AE%B6%E8%AF%B4%E6%98%8E%3A%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 你会发现上面的信息其实是一段一段的，摘取其中的一段为大家说明: <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="swift"><code>"pool-1-thread-1" #10 prio=5 os_prio=0 tid=0x00007f09e0166000 nid=0x7316 runnable [0x00007f09cc9cb000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> at com.tuling.learnjuc.demo.JVMCPU$CPUTask.run(JVMCPU.java:16)</code><code> - locked <0x0000000757d645b8> (a java.lang.Object)</code><code> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)</code><code> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)</code><code> at java.lang.Thread.run(Thread.java:750)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - <0x0000000757d65d00> (a java.util.concurrent.ThreadPoolExecutor$Worker)</code><code> </code></pre> </section> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">pool-1-thread-1</code>:线程名称 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">#1</code>:当前线程ID，从main开始，jvm会根据线程创建的顺序为其线程编号 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">prio</code>:优先级的顺序，一般默认是5 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">os_prio</code>:线程对应系统的优先级 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">tid</code>:java内的线程id <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">nid</code>:操作系统级别的线程id，是一个十六进制 关于线程的信息: <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">NEW</code>:线程新建，还没开始运行 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">RUNNABLE</code>:正在java虚拟机中运行的线程 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">BLOCKED</code>:被阻塞，正在等待监视器锁的线程 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">WAITING</code>:无限期等待另一个线程执行特定操作的线程 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">TIMED_WAITING</code>:等待另一个线程执行操作达到指定等待时间的线程 <code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">TERMINATED</code>:已经退出的线程 我们这里关注的最多的就是<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">nid</code> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22cac793bb%22%2C%22name%22%3A%22h3%22%2C%22attrs%22%3A%7B%22alignment%22%3A%22justify%22%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uc66edf16%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(30%2C%2030%2C%2030)%22%2C%22bgColor%22%3A%22rgb(212%2C%20224%2C%20250)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%222.%E4%BD%BF%E7%94%A8jstack%E8%A7%A3%E5%86%B3CPU%E5%8D%A0%E7%94%A8%E5%BE%88%E9%AB%98%E7%9A%84%E9%97%AE%E9%A2%98%E5%B9%B6%E5%AE%9A%E4%BD%8D%E5%85%B7%E4%BD%93%E8%A1%8C%E6%95%B0%22%7D%5D%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u60a188f0%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ue7737189%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E5%85%88%E6%9D%A5%E7%9C%8B%E4%B8%80%E6%AE%B5%E4%BB%A3%E7%A0%81%3A%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <h3 style="font-size: 20;line-height: 28px;margin: 16px 0 5px 0;text-align: justify;">2.使用jstack解决CPU占用很高的问题并定位具体行数</h3> 先来看一段代码: <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="java"><code>package com.tuling.learnjuc.demo;</code><code> </code><code>import java.util.concurrent.ExecutorService;</code><code>import java.util.concurrent.Executors;</code><code> </code><code>public class JVMCPU {</code><code>    private static ExecutorService service = Executors.newFixedThreadPool(5);</code><code>    private static Object lock = new Object();</code><code>    public static class CPUTask implements Runnable{</code><code> </code><code>        @Override</code><code>        public void run() {</code><code>            synchronized (lock){</code><code>                long sum = 0L;</code><code>                while(true){</code><code>                    sum +=1;</code><code>                }</code><code>            }</code><code>        }</code><code>    }</code><code>    public static void main(String[] args) {</code><code> </code><code>        CPUTask cpuTask = new CPUTask();</code><code>        service.execute(cpuTask);</code><code> </code><code>    }</code><code>}</code></pre> </section> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 将这段代码上传到linux服务器上编译 <blockquote> 注意：如果提示javac: 未找到命令... ，执行yum install java-1.8.0-openjdk-devel </blockquote> <section style="text-align: center;" nodeleaf=""> <img src="/upload/6308f670d43b04544082eea73df6eb9d.png" class="rich_pages wxw-img" data-ratio="0.15648148148148147" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000552"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22ua6fa8133%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uc6d06727%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BD%BF%E7%94%A8%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22ub2fca604%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ub57edd22%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22nohup%20java%20com.tuling.learnjuc.demo.JVMCPU%20%26%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u4b0806c9%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E8%BF%90%E8%A1%8C%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 使用<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">nohup java com.tuling.learnjuc.demo.JVMCPU &</code>运行 <section style="text-align: center;" nodeleaf=""> <img src="/upload/a12b669534709ff59d3119cb89b5d9ba.png" class="rich_pages wxw-img" data-ratio="0.09259259259259259" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000553"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u3956adf8%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uc0f107ee%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BD%BF%E7%94%A8%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u2e993f78%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u9aa59a80%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22top%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u7a5b5797%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E5%91%BD%E4%BB%A4%E5%8F%AF%E4%BB%A5%E7%9C%8B%E5%88%B0cpu%E8%A2%AB%E6%89%93%E6%BB%A1%E4%BA%86%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 使用<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">top</code>命令可以看到cpu被打满了 <section style="text-align: center;" nodeleaf=""> <img src="/upload/705102066230ac8b4e6da507a87ba670.png" class="rich_pages wxw-img" data-ratio="0.2518518518518518" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000554"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u02192818%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u6217cd25%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E7%9F%A5%E9%81%93%E4%BA%86%E8%BF%9B%E7%A8%8B%E7%9A%84PID%EF%BC%8C%E5%A6%82%E4%BD%95%E6%89%BE%E5%88%B0%E8%BF%9B%E7%A8%8B%E4%B8%8B%E6%98%AF%E5%93%AA%E4%B8%AA%E7%BA%BF%E7%A8%8B%E5%91%A2%3F%E5%8F%AF%E4%BB%A5%E4%BD%BF%E7%94%A8%E5%91%BD%E4%BB%A4%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u6e9b242b%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u4d9d0f9e%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22top%20-Hp%2032208%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u733b01bb%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%EF%BC%8C%E5%A6%82%E4%B8%8B%E6%89%80%E7%A4%BA%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 知道了进程的PID，如何找到进程下是哪个线程呢?可以使用命令<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">top -Hp 32208</code>，如下所示 <section style="text-align: center;" nodeleaf=""> <img src="/upload/aad572d136738c1c52b22e0712e02574.png" class="rich_pages wxw-img" data-ratio="0.41759259259259257" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000555"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22ua9754ccd%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u756781cf%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E5%A6%82%E6%9E%9C%E8%83%BD%E8%8E%B7%E5%8F%96%E5%88%B0%E7%BA%BF%E7%A8%8B%E5%90%8D%EF%BC%8C%E4%B8%8B%E9%9D%A2%E8%BF%99%E6%AD%A5%E5%8F%AF%E4%BB%A5%E5%BF%BD%E7%95%A5%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 如果能获取到线程名，下面这步可以忽略，不需要根据线程id找线程 <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <blockquote> 从上面的图可以看到，cpu占用最多的线程是32230这个线程id，接下来就是使用jstack命令来查看程序的所有堆栈信息，但是，这里需要有一个注意的点，32230这个是一个十进制的，使用jstack看到的nid是十六进制，所以我们需要转换，可以使用printf "%x\n"这个命令 </blockquote> <section style="text-align: center;" nodeleaf=""> <img src="/upload/82d59d77bd9a585d0d33e504c255ba3f.png" class="rich_pages wxw-img" data-ratio="0.09235352532274081" data-s="300,640" data-type="png" data-w="1007" type="block" data-imgfileid="100000556"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22uc00ab2f9%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u1c78913f%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E6%8E%A5%E4%B8%8B%E6%9D%A5%E4%BD%BF%E7%94%A8%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u30ca27f7%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u57e962c7%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22jstack%20-l%2032208%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u057484d9%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E6%89%93%E5%8D%B0%E5%A0%86%E6%A0%88%E4%BF%A1%E6%81%AF%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 接下来使用<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">jstack -l 32208</code>打印堆栈信息 <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="sql"><code>[root@192-168-65-185 ~]# jstack -l 32208</code><code>2024-12-17 14:04:09</code><code>Full thread dump OpenJDK 64-Bit Server VM (25.412-b08 mixed mode):</code><code> </code><code>"Attach Listener" #12 daemon prio=9 os_prio=0 tid=0x00007fb498001000 nid=0x4e5 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"DestroyJavaVM" #11 prio=5 os_prio=0 tid=0x00007fb4fc04b800 nid=0x7dd1 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"pool-1-thread-1" #10 prio=5 os_prio=0 tid=0x00007fb4fc16e000 nid=0x7de6 runnable [0x00007fb4e87fe000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> at com.tuling.learnjuc.demo.JVMCPU$CPUTask.run(JVMCPU.java:16)</code><code> - locked <0x0000000757d645b8> (a java.lang.Object)</code><code> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)</code><code> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)</code><code> at java.lang.Thread.run(Thread.java:750)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - <0x0000000757d65d00> (a java.util.concurrent.ThreadPoolExecutor$Worker)</code><code> </code><code>"Service Thread" #9 daemon prio=9 os_prio=0 tid=0x00007fb4fc140000 nid=0x7de4 runnable [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C1 CompilerThread3" #8 daemon prio=9 os_prio=0 tid=0x00007fb4fc133000 nid=0x7de3 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread2" #7 daemon prio=9 os_prio=0 tid=0x00007fb4fc131000 nid=0x7de2 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread1" #6 daemon prio=9 os_prio=0 tid=0x00007fb4fc12f000 nid=0x7de1 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"C2 CompilerThread0" #5 daemon prio=9 os_prio=0 tid=0x00007fb4fc12c800 nid=0x7de0 waiting on condition [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Signal Dispatcher" #4 daemon prio=9 os_prio=0 tid=0x00007fb4fc11e000 nid=0x7ddf runnable [0x0000000000000000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Finalizer" #3 daemon prio=8 os_prio=0 tid=0x00007fb4fc0f2000 nid=0x7dde in Object.wait() [0x00007fb4e92d4000]</code><code>   java.lang.Thread.State: WAITING (on object monitor)</code><code> at java.lang.Object.wait(Native Method)</code><code> - waiting on <0x0000000757d08f00> (a java.lang.ref.ReferenceQueue$Lock)</code><code> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)</code><code> - locked <0x0000000757d08f00> (a java.lang.ref.ReferenceQueue$Lock)</code><code> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:165)</code><code> at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:188)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"Reference Handler" #2 daemon prio=10 os_prio=0 tid=0x00007fb4fc0ed000 nid=0x7ddd in Object.wait() [0x00007fb4e93d5000]</code><code>   java.lang.Thread.State: WAITING (on object monitor)</code><code> at java.lang.Object.wait(Native Method)</code><code> - waiting on <0x0000000757d06b98> (a java.lang.ref.Reference$Lock)</code><code> at java.lang.Object.wait(Object.java:502)</code><code> at java.lang.ref.Reference.tryHandlePending(Reference.java:191)</code><code> - locked <0x0000000757d06b98> (a java.lang.ref.Reference$Lock)</code><code> at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:153)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - None</code><code> </code><code>"VM Thread" os_prio=0 tid=0x00007fb4fc0e3800 nid=0x7ddc runnable </code><code> </code><code>"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007fb4fc05e000 nid=0x7dd2 runnable </code><code> </code><code>"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007fb4fc060000 nid=0x7dd3 runnable </code><code> </code><code>"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x00007fb4fc062000 nid=0x7dd4 runnable </code><code> </code><code>"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x00007fb4fc064000 nid=0x7dd5 runnable </code><code> </code><code>"GC task thread#4 (ParallelGC)" os_prio=0 tid=0x00007fb4fc065800 nid=0x7dd6 runnable </code><code> </code><code>"GC task thread#5 (ParallelGC)" os_prio=0 tid=0x00007fb4fc067800 nid=0x7dd7 runnable </code><code> </code><code>"GC task thread#6 (ParallelGC)" os_prio=0 tid=0x00007fb4fc069800 nid=0x7dd8 runnable </code><code> </code><code>"GC task thread#7 (ParallelGC)" os_prio=0 tid=0x00007fb4fc06b800 nid=0x7dd9 runnable </code><code> </code><code>"GC task thread#8 (ParallelGC)" os_prio=0 tid=0x00007fb4fc06d000 nid=0x7dda runnable </code><code> </code><code>"GC task thread#9 (ParallelGC)" os_prio=0 tid=0x00007fb4fc06f000 nid=0x7ddb runnable </code><code> </code><code>"VM Periodic Task Thread" os_prio=0 tid=0x00007fb4fc142800 nid=0x7de5 waiting on condition </code><code> </code><code>JNI global references: 5</code></pre> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u945352f9%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ua36776a6%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BB%8E%E4%B8%8A%E9%9D%A2%E7%9A%84%E4%BF%A1%E6%81%AF%E4%B8%AD%EF%BC%8C%E5%8F%AF%E4%BB%A5%E7%9C%8B%E5%88%B0%E8%BD%AC%E6%8D%A2%E7%9A%84%E7%BB%93%E6%9E%9C%E5%92%8Cnid%E6%98%AF%E4%B8%80%E8%87%B4%E7%9A%84%EF%BC%8C%22%7D%5D%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u785f5c7c%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uf33a65a8%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BB%8E%E4%B8%8B%E9%9D%A2%E7%9A%84%E4%BF%A1%E6%81%AF%E4%B8%AD%E5%B0%B1%E5%8F%AF%E4%BB%A5%E7%9C%8B%E5%88%B0%E9%97%AE%E9%A2%98%E5%85%B6%E5%AE%9E%E6%98%AF%E5%87%BA%E7%8E%B0%E5%9C%A8%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22ue3e43fb0%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u5a80d1f9%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22JVMCPU.java%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u890b199a%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E7%9A%8416%E8%A1%8C%E5%B7%A6%E5%8F%B3%EF%BC%8C%E8%BF%99%E9%87%8C%E7%BB%99%E5%87%BA%E7%9A%84%E6%98%AF16%E8%A1%8C%EF%BC%8C%E4%BD%86%E6%98%AF%E5%AE%9E%E9%99%85%E6%83%85%E5%86%B5%E6%98%AF16%E8%A1%8C%E7%9A%84%E9%99%84%E8%BF%91%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 从上面的信息中，可以看到转换的结果和nid是一致的， 从下面的信息中就可以看到问题其实是出现在<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">JVMCPU.java</code>的16行左右，这里给出的是16行，但是实际情况是16行的附近 <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="swift"><code>"pool-1-thread-1" #10 prio=5 os_prio=0 tid=0x00007fb4fc16e000 nid=0x7de6 runnable [0x00007fb4e87fe000]</code><code>   java.lang.Thread.State: RUNNABLE</code><code> at com.tuling.learnjuc.demo.JVMCPU$CPUTask.run(JVMCPU.java:16)</code><code> - locked <0x0000000757d645b8> (a java.lang.Object)</code><code> at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)</code><code> at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)</code><code> at java.lang.Thread.run(Thread.java:750)</code><code> </code><code>   Locked ownable synchronizers:</code><code> - <0x0000000757d65d00> (a java.util.concurrent.ThreadPoolExecutor$Worker)</code></pre> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u735539b8%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u1cf8c957%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E7%BB%93%E5%90%88%E4%BB%A3%E7%A0%81%E6%9D%A5%E7%9C%8B%E4%B8%80%E4%B8%8B%E5%B0%B1%E5%BE%88%E5%AE%B9%E6%98%93%E9%97%AE%E9%A2%98%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 结合代码来看一下就很容易问题 <section style="text-align: center;" nodeleaf=""> <img src="/upload/bb317db1e974d25ffad82477018eef05.png" class="rich_pages wxw-img" data-ratio="0.5370370370370371" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000557"> </section> <ne-clipboard source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> <h2 style="font-size: 24px;line-height: 32px;margin: 21px 0 5px 0;text-align: justify;">使用arthas解决CPU占用很高的问题，定位具体代码行</h2> <blockquote> 官方文档：https://arthas.aliyun.com/ </blockquote> 使用arthas解决CPU 100%问题，在方法论上要用到两个命令， <ul style="margin: 0;padding-left: 23px;" class="list-paddingleft-1"> <li>dashboard 命令查看TOP N线程，</li> <li>thread 命令查看堆栈信息</li> </ul> <section style="text-align: center;" nodeleaf=""> <img src="/upload/3d18c01c27599aee3b71ff26de99cd51.png" class="rich_pages wxw-img" data-ratio="0.1875" data-s="300,640" data-type="png" data-w="960" type="block" data-imgfileid="100000558"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22ued510460%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ufc299fb5%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E5%85%88%E6%9D%A5%E8%BF%90%E8%A1%8C%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22uea1befb8%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uf9070dcd%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22arthas%22%7D%5D%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 先来运行<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">arthas</code> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="javascript"><code>curl -O https://arthas.aliyun.com/arthas-boot.jar</code><code>java -jar arthas-boot.jar</code></pre> </section> <section style="text-align: center;" nodeleaf=""> <img src="/upload/e36a50ada6d50c481516880aa0f53d49.png" class="rich_pages wxw-img" data-ratio="0.15648148148148147" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000559"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u9ce49312%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u7fe07ffd%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E8%BE%93%E5%85%A51%E6%98%BE%E7%A4%BA%E5%A6%82%E4%B8%8B%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 输入1显示如下 <section style="text-align: center;" nodeleaf=""> <img src="/upload/88c44b712e6225727d6e40767843f9d1.png" class="rich_pages wxw-img" data-ratio="0.42962962962962964" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000560"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22uf850238f%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u2903f06b%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E8%BE%93%E5%85%A5%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u1b8a3032%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u185ac0da%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22dashboard%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ub9d55c98%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E5%91%BD%E4%BB%A4%E5%8F%AF%E4%BB%A5%E7%9C%8B%E5%88%B0%E6%98%AF%E5%93%AA%E4%B8%AA%E7%BA%BF%E7%A8%8B%E5%8D%A0%E7%94%A8cpu%E6%9C%80%E9%AB%98%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 输入<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">dashboard</code>命令可以看到是哪个线程占用cpu最高 <section style="text-align: center;" nodeleaf=""> <img src="/upload/677ff822ea056b5a88fdd152c7cf7d0b.png" class="rich_pages wxw-img" data-ratio="0.1925925925925926" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000561"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u0cef716e%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ua5a08470%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E6%8E%A5%E4%B8%8B%E6%9D%A5%E8%BE%93%E5%85%A5%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u12324012%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u0ae40b08%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22thread%20-n%201%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u5a90496d%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%EF%BC%8C%E8%A1%A8%E7%A4%BA%E6%9C%80%E5%BF%99%E7%9A%84%E7%BA%BF%E7%A8%8B%E5%B9%B6%E6%89%93%E5%8D%B0%E4%BF%A1%E6%81%AF%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 接下来输入<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">thread -n 1</code>，表示最忙的线程并打印信息 <section style="text-align: center;" nodeleaf=""> <img src="/upload/70b151164fbc3d1a7ac6405d6d11e935.png" class="rich_pages wxw-img" data-ratio="0.1685185185185185" data-s="300,640" data-type="png" data-w="1080" type="block" data-imgfileid="100000562"> </section> <ne-clipboard data="%7B%22type%22%3A%22fragment%22%2C%22name%22%3A%22%23fragment%22%2C%22children%22%3A%5B%7B%22type%22%3A%22element%22%2C%22id%22%3A%22uc738d1c7%22%2C%22name%22%3A%22p%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22uc5f4a49b%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E4%BB%8E%E4%B8%8A%E9%9D%A2%E7%9A%84%E5%9B%BE%E4%B8%AD%E5%8F%AF%E4%BB%A5%E7%9C%8B%E5%88%B0arthas%E5%92%8Cjstack%E5%B1%95%E7%A4%BA%E7%9A%84%E4%BF%A1%E6%81%AF%E5%B7%AE%E4%B8%8D%E5%A4%9A%EF%BC%8C%E9%83%BD%E5%AE%9A%E4%BD%8D%E5%88%B0%E4%BA%86%22%7D%2C%7B%22type%22%3A%22element%22%2C%22id%22%3A%22u97799645%22%2C%22name%22%3A%22code%22%2C%22attrs%22%3A%7B%7D%2C%22children%22%3A%5B%7B%22type%22%3A%22text%22%2C%22id%22%3A%22u2ada2ae5%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A14%7D%2C%22data%22%3A%22JVMCPU.java%22%7D%5D%7D%2C%7B%22type%22%3A%22text%22%2C%22id%22%3A%22ud5a90fda%22%2C%22name%22%3A%22%23text%22%2C%22attrs%22%3A%7B%22color%22%3A%22rgb(36%2C%2041%2C%2046)%22%2C%22fontsize%22%3A16%7D%2C%22data%22%3A%22%E7%9A%8416%E8%A1%8C%E7%A8%8B%E5%BA%8F%22%7D%5D%7D%5D%2C%22attrs%22%3A%7B%7D%7D" source="https%3A%2F%2Fwww.yuque.com%2Fu12222632%2Fas5rgl%2Fkdotyfqesdqxhh8o"></ne-clipboard> 从上面的图中可以看到arthas和jstack展示的信息差不多，都定位到了<code style="font-family: SFMono-Regular, Consolas, Liberation Mono, Menlo, Courier, monospace;background-color: rgba(0, 0, 0, 0.06);border: 1px solid rgba(0, 0, 0, 0.08);border-radius: 2px;padding: 0px 2px;">JVMCPU.java</code>的16行程序

12、 ES 深度分页问题及其解决方案详解

作者：微信小助手

<article> <h2 yne-bulb-block="heading" yne-bulb-level="2" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">1. 什么是深度分页</h2> 深度分页是指在处理大数据集查询时，用户尝试访问多页数据中较后面的页面时遇到的问题。当尝试访问排序后的数据列表的第1000页或更后面的页面时，数据库需要先跳过前面数十万条记录，这一过程通常涉及大量的数据扫描和排序，极大地增加了数据库的查询负载，从而成为性能瓶颈。 ES分页查询流程大致如下： <ol style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 数据存储在各个分片中，协调节点将查询请求转发给各个节点，当各个节点执行搜索后，将排序后的前N条数据返回给协调节点。 </section></li> <li> <section> 协调节点汇总各个分片返回的数据，再次排序，最终返回前N条数据给客户端。 </section></li> <li> <section> 这个流程会导致一个深度分页的问题，也就是翻页越多，性能越差，甚至导致ES出现OOM。 </section></li> </ol> 在分布式系统中，对结果排序的成本随分页的深度成指数上升。 从10万名高考生中查询成绩为的10001-10100位的100名考生的信息。 <section nodeleaf=""> <img src="/upload/c2120a9e540183a1b8e6a807c3188baa.png" class="rich_pages wxw-img" data-ratio="0.5971143174250833" data-type="png" data-w="901" height="384" style="width: 629px;height: 384px;" width="629" data-imgfileid="100000297"> </section> 从上面案例中不难看出，每次有序的查询都会在每个分片中执行单独的查询，然后进行数据的二次排序，而这个二次排序的过程是发生在heap中的，也就是说当你单次查询的数量越大，那么堆内存中汇总的数据也就越多，对内存的压力也就越大。这里的单次查询的数据量取决于你查询的是第几条数据而不是查询了几条数据，比如你希望查询的是第10001-10100这一百条数据，但是ES必须将前10100全部取出进行二次查询。因此，如果查询的数据排序越靠后，就越容易导致OOM（Out Of Memory）情况的发生，频繁的深分页查询会导致频繁的FullGC。 ES为了避免用户在不了解其内部原理的情况下而做出错误的操作，设置了一个阈值，即max_result_window，其默认值为10000，其作用是为了保护堆内存不被错误操作导致溢出。 <h2 yne-bulb-block="heading" yne-bulb-level="2" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">2. 深度分页不推荐使用from+size</h2> 在Elasticsearch中，分页查询的实现主要通过两个参数from和size来实现。from参数指定了从结果集中的第几条数据开始返回，而size参数指定了返回数据的数量。正常情况下分页代码如实下面这样的： </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="css"><code># 查询第一页5条数据</code><code>GET /employee/_search</code><code>{</code><code>  "query": {</code><code>    "match_all": {}</code><code>  },</code><code>  "from": 0,</code><code>  "size": 5  </code><code>}</code></pre> </section> <article> 输出结果如下图： <section nodeleaf=""> <img src="/upload/43a8784098ea2c6fad05cf20d685d27d.png" class="rich_pages wxw-img" data-ratio="1.4823529411764707" data-type="png" data-w="340" height="504" style="width: 340px;height: 504px;" width="340" data-imgfileid="100000299"> </section> 但是如果我们查询的数据页数特别大，当from + size大于10000的时候，就会出现问题，如下图报错信息所示： <section nodeleaf=""> <img src="/upload/a3c241dc22dd8dfbad2fa510b0684b15.png" class="rich_pages wxw-img" data-ratio="0.28055555555555556" data-type="png" data-w="1080" height="503" style="width: 1794px;height: 503px;" width="1794" data-imgfileid="100000300"> </section> 分析可知，查询结果的窗口大小超过了最大窗口的限制，而index. max_result_window默认值为10000。 Elasticsearch会限制最大分页数，避免因大数据量的召回导致系统性能低下。Elasticsearch的max_result_window默认值是10000，意味着每页有10条数据，会最大翻页至1000页。主流搜索引擎实际都翻不了那么多页。 对此，有两个可行的解决方案，如下所示： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 方案一：对于大型数据集，我们可采用scroll API来召回数据。这个策略我们将在后续的内容中进行详细分析。 </section></li> <li> <section> 方案二：调大index.max_result_window默认值 </section></li> </ul> </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="bash"><code>PUT /employee/_settings</code><code>{</code><code>  "index.max_result_window": 20000</code><code>}</code></pre> </section> <article> 官方建议避免使用from+size来过度分页或一次请求太多结果。 不推荐使用from+size来深度分页的核心原因如下： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 搜索请求通常会跨多个分片，每个分片必须将其请求的命中内容以及先前页面的命中内容加载到内存中。 </section></li> <li> <section> 对于分页较多的页面或大量结果，这样操作会显著增加内存和CPU使用率，导致性能下降，甚至导致节点故障。 </section></li> </ul> <h3 yne-bulb-block="heading" yne-bulb-level="3" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">from+size查询的优缺点及适用场景</h3> from+size分页查询的优缺点如下： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> from+size查询优点：支持随机翻页。 </section></li> <li> <section> from+size查询缺点： </section></li> </ul> from+size查询适用场景如下： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 非常适合小型数据集或者从大数据集中返回Top N(N≤10000)结果集的业务场景。 </section></li> <li> <section> 主流PC搜索引擎中支持随机跳转分页的业务场景，如下图所示： </section></li> </ul> <section nodeleaf=""> <img src="/upload/35afb1f9a0f31cf69522060219414d2b.png" class="rich_pages wxw-img" data-ratio="0.5305389221556887" data-type="png" data-w="835" height="443" style="width: 835px;height: 443px;" width="835" data-imgfileid="100000302"> </section> <h2 yne-bulb-block="heading" yne-bulb-level="2" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">3.深度分页问题的常见解决方案</h2> <h3 yne-bulb-block="heading" yne-bulb-level="3" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">尝试避免使用深度分页</h3> 解决深度分页问题最好的办法就是避免使用深度分页。谷歌、百度目前作为全球和国内做大的搜索引擎不约而同的在分页条中删除了“跳页”功能，其目的就是为了避免用户使用深度分页检索。 <section nodeleaf=""> <img src="/upload/35afb1f9a0f31cf69522060219414d2b.png" class="rich_pages wxw-img" data-ratio="0.5305389221556887" data-type="png" data-w="835" height="337" style="width: 606px;height: 337px;" width="606" data-imgfileid="100000303"> </section> 在百度中搜索“Elasticsearch”，在搜索结果中翻到第20页，就无法再往下翻页了，提示信息如下图： <section nodeleaf=""> <img src="/upload/f467a6ed1710cb89b0d3cefa94944426.png" class="rich_pages wxw-img" data-ratio="0.6416666666666667" data-type="png" data-w="1080" height="835" style="width: 1302px;height: 835px;" width="1302" data-imgfileid="100000305"> </section> 淘宝虽然没有删除“跳页”功能，但不管我们搜索什么内容，只要商品结果足够多，返回的商品列表都是仅展示前100页的数据，其本质和ES中的max_result_window作用是一样的，都是限制你去搜索更深页数的数据。 <section nodeleaf=""> <img src="/upload/25371c2068d4ba8a79fbad862105497a.png" class="rich_pages wxw-img" data-ratio="0.3522727272727273" data-type="png" data-w="1056" height="266" style="width: 752px;height: 266px;" width="752" data-imgfileid="100000304"> </section> 手机端APP就更不用说了，直接是下拉加载更多，连分页条都没有，相当于你只能点击“下一页”。 <h3 yne-bulb-block="heading" yne-bulb-level="3" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">Scroll Search滚动查询</h3> scroll API可从单个搜索请求中检索大量结果（甚至所有结果），这种方式与传统数据库中的游标(cursor)类似。scroll滚动遍历查询是非实时的，数据量大的时候，响应时间可能会比较长。 <blockquote> 官方文档：https://www.elastic.co/guide/en/elasticsearch/reference/8.14/paginate-search-results.html#scroll-search-results </blockquote> ES7之后，官方已经不再建议使用scroll API进行深度分页。如果要分页检索超过 Top 10,000+ 结果时，推荐使用：search_after。 <section nodeleaf=""> <img src="/upload/f8121780f02a53f94014c7bb71e5bba0.png" class="rich_pages wxw-img" data-ratio="0.12488350419384903" data-type="png" data-w="1073" height="134" style="width: 1073px;height: 134px;" width="1073" data-imgfileid="100000301"> </section> 适合场景 单个滚动搜索请求中检索大量结果，即非“C端业务”场景 <h4 yne-bulb-block="heading" yne-bulb-level="4" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">实现步骤</h4> scroll查询的核心执行步骤如下。 1) 第一次进行scroll查询，指定检索语句的同时设置scroll上下文保留时间。 scroll请求返回的结果反映了发出初始搜索请求时索引的状态，就像在那一个时刻做了快照，随后对文档的更改（写入、更新或删除）只会影响以后的搜索请求。 <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="swift"><code># 使用kibana提供的航班测试数据集</code><code>#查询命令中新增scroll=5m,说明采用游标查询，保持游标查询窗口5分钟，也就是本次快照的结果缓存起来的有效时间是5分钟。</code><code>GET /kibana_sample_data_flights/_search?scroll=5m </code><code>{</code><code>  "query": {</code><code>    "term": {</code><code>      "OriginWeather": "Sunny"</code><code>    }</code><code>  },</code><code>  "size": 100</code><code>}</code></pre> </section> </article> <article data-content="[{"type":"block","id":"5759-1652538006122","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"BfrC-1688026638080","leaves":[{"text":"返回结果：","marks":[]}]}],"state":{}},{"type":"block","id":"Zkdh-1723984881982","name":"image","data":{"version":1,"url":"https://note.youdao.com/yws/res/f/WEBRESOURCEd42f7ebf11466088efe7cce6fa0b5e4f","width":949,"height":443,"fromIdentity":""},"nodes":[],"state":{"renderSource":"https://note.youdao.com/yws/res/f/WEBRESOURCEd42f7ebf11466088efe7cce6fa0b5e4f","initialSize":{"width":949,"height":443},"loading":false}},{"type":"block","id":"8381-1652538006122","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"PIsS-1688026638080","leaves":[{"text":"2) 向后翻页，继续获取数据，直到没有要返回的结果为止","marks":[{"type":"bold"}]}]}],"state":{}}]"> 返回结果： <section nodeleaf=""> <img src="/upload/6cc1f04accb3292c1593e8d08414561b.png" class="rich_pages wxw-img" data-ratio="0.46680716543730244" data-type="png" data-w="949" height="443" style="width: 949px;height: 443px;" width="949" data-imgfileid="100000306"> </section> 2) 向后翻页，继续获取数据，直到没有要返回的结果为止 </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="swift"><code># scroll_id 的值就是上一个请求中返回的 _scroll_id 的值</code><code>GET /_search/scroll</code><code>{</code><code>    "scroll": "5m", </code><code>    "scroll_id" : "FGluY2x1ZGVfY29udGV4dF91dWlkDXF1ZXJ5QW5kRmV0Y2gBFnQ5MUF6M3dYUkhPQW81czY3RXBDckEAAAAAABkMUBZPOVotS1A1MlI1dU43QXFsdkRGUEhB"</code><code>}</code></pre> </section> <article data-content="[{"type":"block","id":"7mwv-1723984783507","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"VeJU-1723984783506","leaves":[{"text":"多次根据scroll_id游标查询，直到没有数据返回则结束查询。采用游标查询索引全量数据，更安全高效，限制了单次对内存的消耗。","marks":[]}]}],"state":{}},{"type":"block","id":"9263-1653830250250","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"GPxi-1688026638081","leaves":[{"text":"删除游标scroll","marks":[{"type":"bold"}]}]}],"state":{}},{"type":"block","id":"iIR2-1689926903006","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"ASfG-1689926903004","leaves":[{"text":"scroll超过超时后，搜索上下文会自动删除。然而，保持scroll打开是有代价的，因此一旦不再使用，就应明确清除scroll上下文","marks":[]}]}],"state":{}}]"> 多次根据scroll_id游标查询，直到没有数据返回则结束查询。采用游标查询索引全量数据，更安全高效，限制了单次对内存的消耗。 删除游标scroll scroll超过超时后，搜索上下文会自动删除。然而，保持scroll打开是有代价的，因此一旦不再使用，就应明确清除scroll上下文 </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="bash"><code>DELETE /_search/scroll</code><code>{</code><code>    "scroll_id" : "FGluY2x1ZGVfY29udGV4dF91dWlkDXF1ZXJ5QW5kRmV0Y2gBFmNwcVdjblRxUzVhZXlicG9HeU02bWcAAAAAAABmzRY2YlV3Z0o5VVNTdWJobkE5Z3MtXzJB"</code><code>}</code></pre> </section> <article> <h4 yne-bulb-block="heading" yne-bulb-level="4" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">scroll查询的优缺点及适用场景</h4> scroll查询的优缺点如下： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li>scroll查询优点： <section> 支持全量遍历，是检索大量文档的重要方法，但单次遍历的size值不能超过max_result_window的大小。 </section></li> <li>scroll查询缺点：</li> </ul> scroll查询的适用场景如下： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 大量文档检索：当要检索的文档数量很大，甚至需要全量召回数据时，scroll查询是一个很好的选择。 </section></li> <li> <section> 大量文档的数据处理：滚动API适合对大量文档进行数据处理，例如索引迁移或将数据导入其他技术栈。 </section></li> </ul> 注意： 1) ES7.x之后不建议使用scroll API进行深度分页。 2) 如果要分页检索并获得超过10000条结果时，则推荐使用search_after。 <h3 yne-bulb-block="heading" yne-bulb-level="3" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">search_after查询</h3> search_after查询的基本工作原理是以前一页结果的排序值作为参照点，进而检索与这个参照点相邻的下一页的匹配数据。 这种方法在处理大规模数据分页时更为高效且实用。使用该查询的前置条件是要求后续的多个请求返回与第一次查询相同的排序结果序列。也就是说，在后续翻页的过程中，即便有新数据写入等操作，也不会对原有结果集构成影响。 scroll API适用于高效的深度滚动，但滚动上下文成本高昂，不建议将其用于实时用户请求。而search_after参数通过提供一个活动光标来规避这个问题。这样可以使用上一页的结果来帮助检索下一页。 <blockquote> 官方文档：https://www.elastic.co/guide/en/elasticsearch/reference/8.14/paginate-search-results.html#search-after </blockquote> 那么，如何实现呢？ 可以创建一个时间点PIT(Point In Time)来保障在搜索过程中能保留特定事件点的索引状态。search_after的后续查询都是基于PIT视图进行的，能有效保障数据的一致性。 <article data-content="[{"type":"block","id":"eaRk-1723981478698","name":"quote","data":{},"nodes":[{"type":"block","id":"nLBF-1723981475121","name":"paragraph","data":{},"nodes":[{"type":"text","id":"RayY-1723981475119","leaves":[{"text":"PIT是Elasticsearch 7.10版本之后才有的新特性，实际上是存储索引数据状态的轻量级视图。","marks":[]}]}]}],"state":{}},{"type":"block","id":"lu8d-1723981395188","name":"paragraph","data":{"version":1},"nodes":[{"type":"text","id":"y7WA-1723981395187","leaves":[{"text":"","marks":[]}]}],"state":{}}]"> PIT是Elasticsearch 7.10版本之后才有的新特性，实际上是存储索引数据状态的轻量级视图。 </article> </article> <article> <h4 yne-bulb-block="heading" yne-bulb-level="4" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">实现步骤</h4> search_after 分页查询可以简单概括为如下几个步骤： 1）获取索引的pit 使用 search_after 需要具有相同查询和排序值的多个搜索请求。如果在这些请求之间发生刷新，结果的顺序可能会发生变化，从而导致跨页面的结果不一致。为防止出现这种情况，可以创建一个时间点 (PIT) 以保留搜索中的当前索引状态。Point In Time（PIT）是 Elasticsearch 7.10 版本之后才有的新特性。 </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="swift"><code># 使用kibana提供的航班测试数据集</code><code># 创建一个时间点(PIT)来保存搜索期间的当前索引状态</code><code>POST /kibana_sample_data_flights/_pit?keep_alive=5m</code><code>#返回结果如下，会返回一个PID的值</code><code>{</code><code>  "id": "4YyPBAEaa2liYW5hX3NhbXBsZV9kYXRhX2ZsaWdodHMWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAWTzlaLUtQNTJSNXVON0FxbHZERlBIQQAAAAAAABkI4hZ0OTFBejN3WFJIT0FvNXM2N0VwQ3JBAAEWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAA"</code><code>}</code></pre> </section> <article> keep_alive=5m是一个类似于scroll的参数，表示滚动视图的保留时间是5min，超过5min Elasticsearch会清除这个滚动视图并报错，如下图所示 <section nodeleaf=""> <img src="/upload/ddd38ae024262b610c874005b6459e3e.png" class="rich_pages wxw-img" data-ratio="0.2078740157480315" data-type="png" data-w="635" height="132" style="width: 635px;height: 132px;" width="635" data-imgfileid="100000307"> </section> 2）根据pit首次查询 创建基础查询语句，主要是设置分页的条件 </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="bash"><code>GET /_search</code><code>{</code><code>  "query": {</code><code>    "term": {</code><code>      "OriginWeather": "Sunny"</code><code>    }</code><code>  },</code><code>  "pit": {</code><code>    "id": "4YyPBAEaa2liYW5hX3NhbXBsZV9kYXRhX2ZsaWdodHMWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAWTzlaLUtQNTJSNXVON0FxbHZERlBIQQAAAAAAABkI4hZ0OTFBejN3WFJIT0FvNXM2N0VwQ3JBAAEWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAA",</code><code>    "keep_alive": "1m"</code><code>  },</code><code>  "size": 10,</code><code>  "sort": [</code><code>    {</code><code>      "timestamp": "asc"</code><code>    }</code><code>  ]</code><code>}</code></pre> </section> <article> 代码中设置了PIT，因此检索时候就不需要再指定索引。id是基于第一步返回的id值。排序sort指的是按照哪个关键字排序。 在每个返回文档的最后会有两个结果值，如下所示: <section nodeleaf=""> <img src="/upload/9a4cf81d52a8bd62480279d2c4951618.png" class="rich_pages wxw-img" data-ratio="0.20469798657718122" data-type="png" data-w="596" height="122" style="width: 596px;height: 122px;" width="596" data-imgfileid="100000308"> </section> 在每个返回文档的最后会有两个结果值，如下所示。 其中，1723434063000就是我们指定的排序方式，所以上述示例是基于{"timestamp": "asc"}升序排列的。130代表隐含的排序值，官方文档把这种隐含的字段叫作tiebreaker（决胜字段），tiebreaker代表了每个文档的唯一值，确保分页不会丢失或者分页结果数据出现重复（包括相同页重复和跨页重复）。 3）根据search_after和pit实现后续翻页。 要获得下一页结果，请使用最后一次命中的排序值（包括 tiebreaker）作为 search_after 参数重新运行先前的搜索。如果使用 PIT，请在 pit.id 参数中使用最新的 PIT ID。搜索的查询和排序参数必须保持不变。 </article> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="cpp"><code>#后续翻页都需要借助search_after来指定前一页中最后一个文档的sort字段值</code><code>GET /_search</code><code>{</code><code>  "query": {</code><code>    "term": {</code><code>      "OriginWeather": "Sunny"</code><code>    }</code><code>  },</code><code>  "pit": {</code><code>    "id": "4YyPBAEaa2liYW5hX3NhbXBsZV9kYXRhX2ZsaWdodHMWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAWTzlaLUtQNTJSNXVON0FxbHZERlBIQQAAAAAAABkI4hZ0OTFBejN3WFJIT0FvNXM2N0VwQ3JBAAEWZENSdWh0NWNSai1EdUhpcnBCZXgyZwAA",</code><code>    "keep_alive": "5m"</code><code>  },</code><code>  "size": 10,</code><code>  "sort": [</code><code>    {</code><code>      "timestamp": "asc"</code><code>    }</code><code>  ],</code><code>  "search_after": [</code><code>    1723434063000,</code><code>    130</code><code>  ]</code><code>}</code></pre> </section> <article> 显然，search_after查询仅支持向后翻页。 <h4 yne-bulb-block="heading" yne-bulb-level="4" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">优缺点</h4> search_after优点： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 不严格受制于max_result_window，可以无限地往后翻页。此处的“不严格”是指单次请求值不能超过max_result_window，但总翻页结果集可以超过。 </section></li> </ul> search_after缺点： <ul style="margin:0px;margin-left: 14px;" class="list-paddingleft-1"> <li> <section> 只支持向后翻页，不支持随机翻页。search_after不支持随机翻页，更适合在手机端应用的场景中使用，类似今日头条等产品的分页搜索。 </section></li> </ul> <h2 yne-bulb-block="heading" yne-bulb-level="2" style="white-space:pre-wrap;line-height:1.75;font-size:14px;text-align:left;">4. ES三种分页方式总结</h2> <table style="border-collapse:collapse;table-layout:fixed;white-space:nowrap;width:0;"> <caption> <section> </section> </caption> <tfoot> <tr> <td valign="top"> <section> </section></td> </tr> </tfoot> </table> <table> <tbody> <tr style="height: 40px;"> <td valign="top" style="background-color:rgb(240, 240, 240);border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">分页方式</td> <td valign="top" style="background-color:rgb(240, 240, 240);border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">性能</td> <td valign="top" style="background-color:rgb(240, 240, 240);border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">优点</td> <td valign="top" style="background-color:rgb(240, 240, 240);border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">缺点</td> <td valign="top" style="background-color:rgb(240, 240, 240);border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">适用场景</td> </tr> <tr style="height: 40px;"> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">from + size</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">低</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">支持随机翻页</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">受制于max_result_window设置，不能无限制翻页；存在深度翻译问题，越往后翻译越慢。</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">需要随机跳转不同页（PC端主流搜索引擎）；在10000条数据之内分页显示</td> </tr> <tr style="height: 78px;"> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">scroll</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">中</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">支持全量遍历，但单次遍历的size值不能超过max_result_window的大小</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">响应是非实时的；保留上下文需要具有足够的堆内存空间；需要通过更多的网络请求才能获取所有结果。</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">需要遍历全量数据</td> </tr> <tr style="height: 40px;"> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">search_after</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">高</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">不严格受制于max_result_window，可以无限地往后翻页。</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">只支持向后翻页，不支持随机翻页。</td> <td valign="top" style="border:1px solid rgb(167, 167, 167);overflow:hidden;font-size:14px;overflow-wrap:break-word;white-space:pre-wrap;color:rgb(57, 57, 57);">仅需要向后翻页;超过10000条数据，需要分页</td> </tr> </tbody> </table> </article>

解密主流框架中的Netty应用

作者：微信小助手

PlantUML画时序图，真香！

作者：微信小助手

<section data-tool="mdnice编辑器" data-website="https://www.mdnice.com" style="margin-bottom: 0px;padding-left: 10px;padding-right: 10px;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;width: auto;font-family: Optima, " microsoft yahei, pingfangsc-regular, serif;font-size: 16px;color: rgb(0, 0, 0);line-height: 1.5em;word-spacing: 0em;letter-spacing: 0em;word-break: break-word;text-align: left; data-mpa-powered-by="yiban.io"> <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">引言</h1> 大家好，我是老三，最近在做系统设计的时候，发现要画不少时序图，以前我用的最顺手的工具是draw.io，后来也尝试了语雀自带的画图工具，感觉画画简单的图还行，但是复杂一点的，就比较吃力了。<img class="rich_pages wxw-img" data-imgfileid="100012106" data-ratio="0.6231481481481481" src="/upload/ff87ceb3bf3373e7ba337ad3765e0f47.png" data-type="png" data-w="1080" style="display: block;margin-right: auto;margin-left: auto;">哎，这条线怎么又歪了？布局怎么又乱了？这个条怎么又对不齐了？……手忙脚乱才画好一张图，这时候我就想，有没有其它更专业的画图工具呢？大部分同事都在用Visio，辉哥给我推荐了PlantUML，说非常好用！这时候旁边来了一句—— “他就是装比！” <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012105" data-ratio="0.6866666666666666" src="/upload/1c076c802a01ffdf3089355bc706ccb4.png" data-type="gif" data-w="150" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 装比带我一个 </figcaption> </figure>  还有这样的事？那我不能让他一个人都装了。 最开始看下官方文档，发现PlantUML类似MarkDown，似乎需要一点学习成本，简单用了一下，曲线还是挺平缓的，上手相当快！推荐大家也用一下试试。 <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">一、什么是PlantUML？</h1> <blockquote data-tool="mdnice编辑器" style="margin-top: 20px;margin-bottom: 20px;padding: 10px 10px 10px 20px;border-top: 3px none rgba(0, 0, 0, 0.4);border-bottom: 3px none rgba(0, 0, 0, 0.4);border-right: 3px none rgba(0, 0, 0, 0.4);border-left-color: rgb(53, 179, 120);border-radius: 0px;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgb(251, 249, 253);width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;overflow: auto;"> <strong style="color: rgb(74, 74, 74);background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(0, 0, 0, 0);width: auto;height: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 0px;">PlantUML是一个多功能组件，可快速、直接地创建图表。用户可以使用简单直观的语言起草各种图表。 </blockquote> PlantUML是一个开源工具，它允许我们用简单的文本描述来创建UML图，包括序列图、用例图、类图、对象图、活动图、组件图、部署图、状态图，以及我们今天要讲的时序图。<img class="rich_pages wxw-img" data-imgfileid="100012104" data-ratio="0.4715909090909091" src="/upload/309b78c467ee86c76f8c221c9c90d7d7.png" data-type="png" data-w="1056" style="display: block;margin-right: auto;margin-left: auto;">除了UML图之外，PlantUML 还支持一系列其他图表，例如JSON数据、YAML数据、EBNF图表、架构图等等。PlantUML的一大优势，是图表完全用文本代码描述，这就意味着它可以作为文档嵌入到源代码中，也非常方便版本控制和多人协作，不管是迭代设计、文档编写、系统建模，PlantUML都能胜任。 <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">二、快速入门</h1> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">PlantUML插件</h2> 为了便捷地使用PlantUML，许多流行的IDE和代码编辑器提供了集成PlantUML的插件，如Visual Studio Code、IntelliJ IDEA、Eclipse等。插件提供了实时预览、语法高亮和图表导出等功能，能帮助我们更快捷，更高效地画图，整体上IDEA的插件用起来体验最好，但是IDEA大家懂的，太占内存了，VS Code相对而言，用起来就会轻量很多。 <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> IntelliJ IDEA：比如 "PlantUML integration" 可以让我们直接在 IDE 中查看和编辑 PlantUML 图表 <figure style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012107" data-ratio="0.737037037037037" src="/upload/f67cb608f92c4530eaf5d8c179c4cb7b.png" data-type="png" data-w="1080" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> PlantUML integration </figcaption> </figure> </section></li> <ul style="list-style-type: square;margin-top: 8px;margin-bottom: 8px;padding-left: 25px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 插件使用效果 </section></li> </ul> </ul> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012108" data-ratio="0.46111111111111114" src="/upload/3d9f16dac8931a7db574014f7633f677.png" data-type="png" data-w="1080" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> image.png </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> VS Code：https://marketplace.visualstudio.com/items?itemName=jebbs.plantuml </section></li> <ul style="list-style-type: square;margin-top: 8px;margin-bottom: 8px;padding-left: 25px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 插件市场： </section></li> </ul> </ul> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012112" data-ratio="0.6981481481481482" src="/upload/3f000d36c8b05d5e9f4591c8a8561329.png" data-type="png" data-w="1080" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> image.png </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 插件使用效果： </section></li> </ul> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012113" data-ratio="0.5537037037037037" src="/upload/2dac24f33630e93aa83ff4ac2e0121de.png" data-type="png" data-w="1080" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> image.png </figcaption> </figure> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">Hello World!</h2> 我们先来看个最简单的例子，通过<code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>-></code> 、<code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>--></code>和<code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;> :</code>就可以在参与者之间传递消息，不用明确声明参与者。 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml 老张 -> 老王 : 老王，你好啊 老王--> 老张: 老张，你好啊 老张 -> 老王: 最近有空一起喝茶 老张 <-- 老王: OK @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012109" data-ratio="1.2377777777777779" src="/upload/7031b84b4b941faf897916f4384d5b98.png" data-type="png" data-w="450" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> hello </figcaption> </figure> <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">三、PlantUML时序图语法</h1> 接下来，我们看看PlantUML时序图的一些具体语法。 <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">声明参与者</h2> 我们使用关键字participant 来声明参与者，就可以对该参与者进行更多的控制。声明的顺序就是默认的<strong style="color: rgb(74, 74, 74);background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 0px;">显示顺序。我们也可以用这些关键字来声明参与者，给参与者设置不同的形状。 <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> actor（角色） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> boundary（边界） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> control（控制） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> entity（实体） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> database（数据库） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> collections（集合） </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> queue（队列） </section></li> </ul> 我们还可以通过 <code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>as</code>关键字重命名参与者。 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml participant Participant as Foo actor       Actor       as Foo1 boundary    Boundary    as Foo2 control     Control     as Foo3 entity      Entity      as Foo4 database    Database    as Foo5 collections Collections as Foo6 queue       Queue       as Foo7 @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012110" data-ratio="0.3225419664268585" src="/upload/297e0600ba7b1b74df24823626fc935d.png" data-type="png" data-w="834" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 参与者 </figcaption> </figure> 默认的颜色比较单调，也可以通过<code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>#</code>来设置参与者的颜色： <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml actor Bob #blue ' The only difference between actor 'and participant is the drawing participant Alice #SkyBlue participant "I have a really\nlong name" as L #00ff00 Alice->Bob: Authentication Request Bob->Alice: Authentication Response Bob->L: Log transaction @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012111" data-ratio="0.8607038123167156" src="/upload/cb3fe7d790dda89c1766c13868b3659d.png" data-type="png" data-w="682" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 上颜色的参与者 </figcaption> </figure> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">消息传递</h2> 在不同参与者之间，通过箭头+:来表示消息传递。 <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 同步消息： </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">A -> B: 同步消息文本 </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012115" data-ratio="0.9397163120567376" src="/upload/f25483af4ba1f4673aa1771832b96c0f.png" data-type="png" data-w="282" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 同步消息 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 异步消息：由发送者A指向接收者B，表示A发送后不需要等待B立即处理。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">A ->> B: 异步消息文本 </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012118" data-ratio="0.9408284023668639" src="/upload/a3b74cf0c49f24f66935f368cddf1bc3.png" data-type="png" data-w="338" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 异步消息 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 返回消息：通常从接收者返回到发送者，标识一个回应。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">A <-- B: 返回消息文本 </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012114" data-ratio="0.9408284023668639" src="/upload/fdacd8718cd74973b92c5d215b6eb540.png" data-type="png" data-w="338" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 返回消息 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 自调用：一个参与者直接发送消息给自己，表示自我处理或运算。 <pre style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;color: rgb(171, 178, 191);width: auto;margin-left: 2px;margin-right: 2px;padding: 15px 4px 2px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);word-break: break-all;background: rgb(40, 44, 52);display: -webkit-box;font-family: " operator mono, consolas, monaco, menlo, monospace;border-radius: 0px;font-size: 12px;>A ->A: 自调用 </code></pre> <figure style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012117" data-ratio="2.0406976744186047" src="/upload/b139dc43cef7646d7004c800b1a840ef.png" data-type="png" data-w="172" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 自调用 </figcaption> </figure> </section></li> </ul> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">生命线（Lifeline）与激活条（Activation Bar）</h2> 在时序图中，生命线表示对象在一段时间内的活动状态，也就是从参与者往下延伸的那条虚线。激活条用来表示参与者或对象在处理某个任务期间的活动状态，是生命线的一部分，矩形条形式出现。 <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 生命线的激活与撤销：可以用下面这些关键字来控制生命线的激活与撤销 </section></li> <ul style="list-style-type: square;margin-top: 8px;margin-bottom: 8px;padding-left: 25px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> activate: 显示参与者的活动状态开始 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> deactivate: 指示参与者的活动状态结束。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> destroy: 用于表示参与者的生命线终结，通常表示对象生命周期的结束。 </section></li> </ul> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml participant User User -> A: DoWork activate A A -> B: << createRequest >> activate B B -> C: DoWork activate C C --> B: WorkDone destroy C B --> A: RequestCreated deactivate B A -> User: Done deactivate A @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012116" data-ratio="0.8515463917525773" src="/upload/c74387e681d903d2ff2526c17fae0bf2.png" data-type="png" data-w="485" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 生命线的激活与撤销 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 生命线的嵌套与颜色：我们还可以使用嵌套激活条来表示内部调用，并可以给生命线添加颜色。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml participant User User -> A: DoWork activate A #FFBBBB A -> A: Internal call activate A #DarkSalmon A -> B: << createRequest >> activate B B --> A: RequestCreated deactivate B deactivate A A -> User: Done deactivate A @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012122" data-ratio="1.088992974238876" src="/upload/604e66046aba4639d92f0cc693dd97db.png" data-type="png" data-w="427" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 生命线的嵌套与颜色 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 自动激活：在发送消息时自动显示激活条。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">A->B++: 激活B并发送消息 </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012120" data-ratio="0.8079268292682927" src="/upload/9e795f7d95d6d47f5785343fe21e8395.png" data-type="png" data-w="328" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 自动激活 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 自动去激活：在接收回应时自动隐藏激活条。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">A->B++: 激活B并发送消息 A <--B--: B去激活并回应消息 </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012124" data-ratio="0.9095890410958904" src="/upload/9f4defcf1a483d61662ea4eb3c146357.png" data-type="png" data-w="365" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 自动去激活 </figcaption> </figure> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">分组和替代</h2> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 分组：用于逻辑上分组一系列交互。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">group 分组名 A -> B: 消息 ... end group </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012121" data-ratio="1.7433628318584071" src="/upload/e7100f2cfd0d21132a6aa6d7b66cec7e.png" data-type="png" data-w="226" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 分组 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 替代（Alt/Else）：表示基于条件的替代执行流程。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">alt 条件1 A -> B: 满足条件1的消息 else 条件2 A -> B: 满足条件2的消息 end </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012123" data-ratio="1.1624203821656052" src="/upload/5fca183fc5a2d4f0e86c24b6c9434b45.png" data-type="png" data-w="314" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 替代 </figcaption> </figure> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">注释</h2> 注释用于添加说明性文本。 <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 可以用note left of，note right of或note over来控制注释相对节点的位置，还可以通过修改背景色来高亮显示注释。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml participant Alice participant Bob note left of Alice #aqua This is displayed left of Alice. end note note right of Alice: This is displayed right of Alice. note over Alice: This is displayed over Alice. note over Alice, Bob #FFAAAA: This is displayed\n over Bob and Alice. note over Bob, Alice This is yet another example of a long note. end note @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012128" data-ratio="1.055441478439425" src="/upload/85fa9596bc9fe5d3ade903f06596066a.png" data-type="png" data-w="487" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 注释 </figcaption> </figure> <h2 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_png pmzoeonjxwc5p16tqysanspnkbrxfxxfh0iaicjh4eraszazhu0qdcliaibiaib5o7rqxib2tnmlej1x74xjyyonrdk9a 640?wx_fmt="png&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 63px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">颜色</h2> Choosing colors在 PlantUML 中，我们可以对时序图的各个元素自定义颜色，比如参与者（actors）、对象（objects）、激活条（activation bars)等，来让我们的时序图更加美观。在声明元素时，可以直接指定颜色，格式为#颜色代码。颜色代码可以是不同的形式： <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 直接指定颜色：颜色代码可以是一个十六进制颜色值，也可以是预定义的颜色名称。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml actor 用户  #Green participant 参与者  #B4A7E5 用户-[#red]>参与者:消息 activate 参与者 #Blue @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012125" data-ratio="1.9739130434782608" src="/upload/44f17b8e66ed9c747c0815e9dc0c7e64.png" data-type="png" data-w="230" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 直接指定颜色 </figcaption> </figure> <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 使用 <code style="background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>skinparam</code> 设置颜色：除了直接为特定元素指定颜色外，还可以使用 <code style="background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>skinparam</code> 全局设置时序图中的颜色。用这种方式更改元素的默认颜色比较方便： </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml skinparam ActorBorderColor #DarkOrange skinparam ParticipantBackgroundColor #SkyBlue actor 用户 participant 参与者 @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012127" data-ratio="1.6869565217391305" src="/upload/05d2d28b9266bdc76217160a91f84a2b.png" data-type="png" data-w="230" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 使用 <code>skinparam</code> 设置颜色 </figcaption> </figure> 当使用 <code style="color: rgb(40, 202, 113);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background: none 0% 0% / auto no-repeat scroll padding-box border-box rgba(27, 31, 35, 0.05);width: auto;height: auto;margin-left: 2px;margin-right: 2px;padding: 2px 4px;border-style: none;border-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 4px;font-family: " operator mono, consolas, monaco, menlo, monospace;word-break: break-all;>skinparam</code> 时，我们可以设置许多不同属性的颜色，如边框颜色（BorderColor）、背景颜色（BackgroundColor）、字体颜色（FontColor）和激活条颜色（SequenceGroupBodyBackgroundColor）。更多语法可以直接查看官方文档：顺序图的语法和功能，目前这些内容，已经足够我们常见的时序图需求了。 <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">四、完整实例</h1> 我们接下来看一个稍微完整一点的例子，在这个例子中，我们的需求，是要在原本的登录的基础上，引入Google登录。 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;margin-top: 10px;margin-bottom: 10px;"><span style="display: block;background: url(" https: mmbiz.qpic.cn mmbiz_svg iahdqiccc5vbskyvchl3yzerhnm8cv0eribia6kxszvzrfthxrcn46sxzylwhefibb5fp8bicgummdghws2e8cur8qzy02zdldnaria 640?wx_fmt="svg&from=appmsg")" 10px 40px no-repeat rgb(40, 44, 52);height: 30px;width: 100%;margin-bottom: -7px;border-radius: 5px;><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;font-size: 12px;">@startuml skinparam ParticipantBackgroundColor #DeepSkyBlue actor 用户 as c  #DeepSkyBlue participant "客户端" as client participant "服务网关" as ga participant "用户服务" as user database "数据库" as DB  #DeepSkyBlue participant "Google服务" as google  #LightCoral activate c #DeepSkyBlue activate client #DeepSkyBlue c->client:用户登录 group#LightCoral #LightCoral Google登录客户端流程   client -> google : 请求Google OAuth登录             activate google #DeepSkyBlue             google-->client:登录url             client->google:跳转登录页             google -> google : 用户登录             google --> client : Google登录Token             deactivate google end ||| client -> ga : 登录请求 note right#LightCoral:新增登录方式，三方登录请求实体 activate ga #DeepSkyBlue ga ->user:请求转发 activate user #DeepSkyBlue alt#DeepSkyBlue 常规登录     user -> DB : 查询用户信息     activate DB #DeepSkyBlue     DB -> user : 用户信息     deactivate DB     user->user:登录密码校验 ||| else Google登录     group#LightCoral #LightCoral Google登录服务端流程           user->google:验证token           activate google #DeepSkyBlue           google-->user:用户信息           deactivate google           user->user:存储或更新用户信息     end group end user-->ga:登录结果 deactivate user ga -> client : 响应 deactivate ga alt#DeepSkyBlue 成功         client -> c : 登录成功 else 失败         client -> c : 登录失败 end deactivate client ||| @enduml </code></pre> <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100012129" data-ratio="1.7737512242899118" src="/upload/d35a0f3d54b426c0500f40eb0cf93576.png" data-type="png" data-w="1021" style="display: block;margin-right: auto;margin-left: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 4px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 12px;line-height: 1.5em;letter-spacing: 0em;text-align: center;margin-top: 5px;"> 登录时序图 </figcaption> </figure> <h1 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;background-attachment: scroll;background-clip: border-box;background-image: url(" https: mmbiz.qpic.cn mmbiz_jpg pmzoeonjxwc5p16tqysanspnkbrxfxxfqzjf2xcbjibnwrswd6iciajlnr8lhjoqg8nhwqaido8ow6kizvibyvc0yq 640?wx_fmt="other&from=appmsg");background-origin:" padding-box;background-position: 50% 50%;background-repeat: no-repeat;background-size: 75px;width: auto;height: auto;align-items: unset;border-style: none;border-width: 1px;border-color: rgb(0, 0, 0);border-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;justify-content: center;line-height: 1.5em;overflow: unset;text-shadow: none;transform: none;-webkit-box-reflect: unset;><span style="font-size: 18px;color: rgb(72, 179, 120);line-height: 2.4em;letter-spacing: 0em;margin-top: 38px;margin-bottom: 10px;border-style: none none solid;border-width: 1px 1px 2px;border-color: rgb(0, 0, 0) rgb(0, 0, 0) rgb(46, 121, 80);border-radius: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;box-shadow: none;display: inline-block;font-weight: bold;flex-direction: unset;float: unset;height: 38px;justify-content: unset;overflow: unset;text-align: center;text-indent: 0em;text-shadow: none;transform: none;width: auto;-webkit-box-reflect: unset;">五、总结</h1> PlantUML使用起来整体上还是非常舒服的，对我而言，这几个特点让我爱不释手： <ul data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 提供了类似MarkDown的所见即所得的使用体验，免去调整图形之扰 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> PlantUML本质是文本，可以进行版本控制，多人协同 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 语雀支持文本画图的功能，可以嵌入PlantUML文本，支持在语雀文档里直接修改 </section></li> </ul> PlantUML还有很强大的扩展性和灵活性，我们可以通过官方文档：<span style="color: rgb(91, 128, 141);font-family: Vollkorn, Palatino, Times;letter-spacing: normal;orphans: 4;text-align: start;white-space: pre-wrap;word-spacing: 0.85px;background-color: rgb(255, 255, 255);text-decoration: underline;">https://plantuml.com/zh/ 继续探索更多高级语法和技巧，来绘制更加复杂和丰富的图表。 <hr data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;border-style: none;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-color: rgb(0, 0, 0) rgba(0, 0, 0, 0.4) rgba(0, 0, 0, 0.4);border-radius: 0px;background: linear-gradient(90deg, rgba(93, 186, 133, 0) 0%, rgba(93, 186, 133, 0.75) 50%, rgba(93, 186, 133, 0) 100%) 0% 0% / auto no-repeat scroll padding-box border-box rgba(255, 255, 255, 0);width: auto;height: 2px;"> <strong style="color: rgb(74, 74, 74);background-attachment: scroll;background-clip: border-box;background-image: none;background-origin: padding-box;background-position: 0% 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;border-style: none;border-width: 3px;border-color: rgba(0, 0, 0, 0.4);border-radius: 0px;">参考： <ol data-tool="mdnice编辑器" style="margin-top: 8px;margin-bottom: 8px;padding-left: 25px;" class="list-paddingleft-1"> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 开源工具，使用简单的文字描述画UML图 </section></li> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> Choosing colors </section></li> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 顺序图的语法和功能 </section></li> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 如何使用 PlantUML 画系统设计图？- 掘金 </section></li> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> 顺序图的语法和功能 </section></li> <li style="font-size: 10px;"> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(63, 63, 63);line-height: 1.8em;letter-spacing: 0.02em;"> GPT老师 </section></li> </ol> </section>

SpringBoot 实现 License 认证：快速校验有效期的简洁方案

作者：微信小助手

<img class="rich_pages wxw-img" data-imgfileid="100015609" data-ratio="0.5714285714285714" data-s="300,640" src="/upload/5e98b50f0a7c61f3ccf1310a77e91fa9.png" data-type="png" data-w="1792" style="height: 330px;width: 578px;"> <section style="margin-bottom: 0px;letter-spacing: 0.578px;text-wrap: wrap;line-height: 2em;"> <span style="letter-spacing: 0.578px;font-family: mp-quote, -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: var(--articlefontsize);> </section> <p data-sourcepos="1:1-1:75" style="box-sizing: border-box;margin-top: 0px !important;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>SpringBoot 实现 License 认证：快速校验有效期的简洁方案 <p data-sourcepos="3:1-3:789" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>在现代软件开发中，特别是商业软件领域，License认证是一种至关重要的技术，用于限制软件的使用范围和授权模式。它不仅保护开发者的利益，也为用户提供合法使用的依据。License认证通常涉及生成密钥对、签发证书以及验证有效性等步骤，这些过程虽然复杂，但通过适当的工具和技术可以简化实现。在本篇文章中，我们将基于 SpringBoot 框架，结合 TrueLicense 开源工具，展示如何快速实现 License 认证，尤其是围绕“有效期校验”的核心功能。通过阅读本文，您将掌握如何生成密钥对、创建 License 证书以及如何在项目中集成并校验证书的有效性，助力您构建更加安全可靠的软件系统。 <h3 data-sourcepos="5:1-5:18" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>License 简介</h3> <p data-sourcepos="7:1-7:104" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>License 即版权许可证书，用于为收费软件提供访问许可证明，常见于以下场景： <ul style="box-sizing: border-box;padding-left: 2rem;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none; class="list-paddingleft-1"> <li style="box-sizing: border-box;">应用场景 <section> <section> 部署在客户内网环境，开发者无法控制其网络状态，需通过离线方式校验证书有效性。 </section> </section></li> <li style="box-sizing: border-box;margin-top: 0.25rem;">授权原理 <section> <section> 利用证书管理工具生成密钥对，私钥用于创建 License 证书，公钥验证其合法性和有效期。 </section> </section></li> </ul> <h3 data-sourcepos="14:1-14:28" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>授权者生成密钥对</h3> <p data-sourcepos="16:1-16:86" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>授权者通过 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>Keytool</code> 工具生成私钥和公钥，并完成证书库的管理。 <pre data-sourcepos="18:1-28:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;># 生成私钥库 keytool -genkeypair-keysize2048-validity3650-alias"privateKey"-keystore"privateKeys.keystore"-storepass"myStorePass123"-keypass"myKeyPass123"-dname"CN=localhost, OU=localhost, O=localhost, L=SH, ST=SH, C=CN" # 导出公钥到文件 keytool -exportcert-alias"privateKey"-keystore"privateKeys.keystore"-storepass"myStorePass123"-file"certfile.cer" # 导入证书到公钥库 keytool -import-alias"publicCert"-file"certfile.cer"-keystore"publicCerts.keystore"-storepass"myStorePass123" </code></pre> <h3 data-sourcepos="30:1-30:34" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>授权者生成 License 文件</h3> <h4 data-sourcepos="32:1-32:17" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>Maven 依赖</h4> <p data-sourcepos="34:1-34:74" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>在项目的 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>pom.xml</code> 文件中添加 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>TrueLicense</code> 的核心库依赖： <pre data-sourcepos="36:1-42:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;><dependency>     <groupId>de.schlichtherle.truelicensegroupId>     <artifactId>truelicense-coreartifactId>     <version>1.33version> dependency> </code></pre> <p data-sourcepos="44:1-44:17" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>License 生成类 <p data-sourcepos="46:1-46:56" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>以下代码实现了 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>License</code> 文件的生成逻辑。 <pre data-sourcepos="48:1-124:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importde.schlichtherle.license.*; importlombok.extern.slf4j.Slf4j; importjavax.security.auth.x500.X500Principal; importjava.io.File; importjava.util.Date; importjava.util.prefs.Preferences; @Slf4j publicclassLicenseCreator{     privatestaticfinalX500PrincipalDEFAULT_HOLDER_AND_ISSUER=             newX500Principal("CN=localhost, OU=localhost, O=localhost, L=SH, ST=SH, C=CN");     publicstaticvoidmain(String[] args){         LicenseCreatorParam param =newLicenseCreatorParam();         param.setSubject("license");         param.setPrivateAlias("privateKey");         param.setKeyPass("myKeyPass123");         param.setStorePass("myStorePass123");         param.setLicensePath("license.lic");         param.setPrivateKeysStorePath("privateKeys.keystore");         param.setIssuedTime(newDate());         param.setExpiryTime(newDate(System.currentTimeMillis()+10L*365*24*60*60*1000));         param.setConsumerType("user");         param.setConsumerAmount(1);         param.setDescription("This is a license file.");         try{             newLicenseCreator().generateLicense(param);             log.info("License file generated successfully at: {}", param.getLicensePath());         }catch(Exception e){             log.error("Failed to generate license file", e);         }     }     publicvoidgenerateLicense(LicenseCreatorParam param){         try{             LicenseManager licenseManager =newLicenseManager(initLicenseParam(param));             LicenseContent licenseContent =initLicenseContent(param);             licenseManager.store(licenseContent,newFile(param.getLicensePath()));         }catch(Exception e){             log.error("License generation failed", e);         }     }     privatestaticLicenseParaminitLicenseParam(LicenseCreatorParam param){         Preferences preferences =Preferences.userNodeForPackage(LicenseCreator.class);         CipherParam cipherParam =newDefaultCipherParam(param.getStorePass());         KeyStoreParam privateStoreParam =newCustomKeyStoreParam(                 LicenseCreator.class,                 param.getPrivateKeysStorePath(),                 param.getPrivateAlias(),                 param.getStorePass(),                 param.getKeyPass()         );         returnnewDefaultLicenseParam(param.getSubject(), preferences, privateStoreParam, cipherParam);     }     privatestaticLicenseContentinitLicenseContent(LicenseCreatorParam param){         LicenseContent content =newLicenseContent();         content.setHolder(DEFAULT_HOLDER_AND_ISSUER);         content.setIssuer(DEFAULT_HOLDER_AND_ISSUER);         content.setSubject(param.getSubject());         content.setIssued(param.getIssuedTime());         content.setNotBefore(param.getIssuedTime());         content.setNotAfter(param.getExpiryTime());         content.setConsumerType(param.getConsumerType());         content.setConsumerAmount(param.getConsumerAmount());         content.setInfo(param.getDescription());         return content;     } } </code></pre> <h4 data-sourcepos="126:1-126:28" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>LicenseCreatorParam 类</h4> <pre data-sourcepos="128:1-152:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importcom.fasterxml.jackson.annotation.JsonFormat; importlombok.Data; importjava.util.Date; @Data publicclassLicenseCreatorParam{     privateString subject;     privateString privateAlias;     privateString keyPass;     privateString storePass;     privateString licensePath;     privateString privateKeysStorePath;     @JsonFormat(pattern ="yyyy-MM-dd HH:mm:ss", timezone ="GMT+8")     privateDate issuedTime;     @JsonFormat(pattern ="yyyy-MM-dd HH:mm:ss", timezone ="GMT+8")     privateDate expiryTime;     privateString consumerType;     privateInteger consumerAmount;     privateString description; } </code></pre> <h4 data-sourcepos="154:1-154:28" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>CustomKeyStoreParam 类</h4> <pre data-sourcepos="156:1-191:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importde.schlichtherle.license.AbstractKeyStoreParam; publicclassCustomKeyStoreParamextendsAbstractKeyStoreParam{     privatefinalString storePath;     privatefinalString alias;     privatefinalString storePwd;     privatefinalString keyPwd;     publicCustomKeyStoreParam(Class<?> clazz,String storePath,String alias,String storePwd,String keyPwd){         super(clazz, storePath);         this.storePath = storePath;         this.alias = alias;         this.storePwd = storePwd;         this.keyPwd = keyPwd;     }     @Override     publicStringgetAlias(){         return alias;     }     @Override     publicStringgetStorePwd(){         return storePwd;     }     @Override     publicStringgetKeyPwd(){         return keyPwd;     } } </code></pre> <h3 data-sourcepos="193:1-193:25" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>使用者配置验证</h3> <p data-sourcepos="195:1-195:116" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>使用者需在项目中加载 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>publicKeys.keystore</code> 和 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>license.lic</code> 文件，并在应用启动时进行校验。 <ul style="box-sizing: border-box;padding-left: 2rem;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none; class="list-paddingleft-1"> <li style="box-sizing: border-box;">校验逻辑 <section> ：通过公钥验证证书的合法性及有效期。 </section></li> <li style="box-sizing: border-box;margin-top: 0.25rem;">安全建议 <section> ：妥善保护私钥文件，不得泄露给使用者。 </section></li> </ul> <h3 data-sourcepos="200:1-200:56" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>基于 TrueLicense 的 License 验证与安装优化</h3> <p data-sourcepos="202:1-202:169" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>本文将详细介绍如何在项目中通过 TrueLicense 实现 License 的验证与安装。以下优化后的代码和配置旨在满足不同使用场景的需求。 <h4 data-sourcepos="204:1-204:34" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>使用者的 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>pom.xml</code> 配置</h4> <pre data-sourcepos="205:1-212:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;> <dependency>     <groupId>de.schlichtherle.truelicensegroupId>     <artifactId>truelicense-coreartifactId>     <version>1.33version> dependency> </code></pre> <h4 data-sourcepos="214:1-214:22" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>License 校验类</h4> <p data-sourcepos="215:1-215:51" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>创建 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>com.icoderoad.license.LicenseVerify</code> 类： <pre data-sourcepos="217:1-279:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importde.schlichtherle.license.*; importlombok.Data; importlombok.extern.slf4j.Slf4j; importjava.io.File; importjava.text.DateFormat; importjava.text.MessageFormat; importjava.text.SimpleDateFormat; importjava.util.prefs.Preferences; @Slf4j publicclassLicenseVerify{     // 安装 License 证书     publicsynchronizedLicenseContentinstall(LicenseVerifyParam param){         LicenseContent result =null;         DateFormat format =newSimpleDateFormat("yyyy-MM-dd HH:mm:ss");         try{             LicenseManager licenseManager =LicenseManagerHolder.getInstance(initLicenseParam(param));             licenseManager.uninstall();             result = licenseManager.install(newFile(param.getLicensePath()));             log.info(MessageFormat.format("证书安装成功，证书有效期：{0} - {1}",                      format.format(result.getNotBefore()), format.format(result.getNotAfter())));         }catch(Exception e){             log.error("证书安装失败: {}", e.getMessage());         }         return result;     }     // 校验 License 证书     publicbooleanverify(){         LicenseManager licenseManager =LicenseManagerHolder.getInstance(null);         DateFormat format =newSimpleDateFormat("yyyy-MM-dd HH:mm:ss");         try{             LicenseContent licenseContent = licenseManager.verify();             log.info(MessageFormat.format("证书校验通过，证书有效期：{0} - {1}",                      format.format(licenseContent.getNotBefore()), format.format(licenseContent.getNotAfter())));             returntrue;         }catch(Exception e){             log.error("证书校验失败: {}", e.getMessage());             returnfalse;         }     }     // 初始化证书生成参数     privateLicenseParaminitLicenseParam(LicenseVerifyParam param){         Preferences preferences =Preferences.userNodeForPackage(LicenseVerify.class);         CipherParam cipherParam =newDefaultCipherParam(param.getStorePass());         KeyStoreParam publicStoreParam =newCustomKeyStoreParam(LicenseVerify.class,                 param.getPublicKeysStorePath(),                 param.getPublicAlias(),                 param.getStorePass(),                 null);         returnnewDefaultLicenseParam(param.getSubject(), preferences, publicStoreParam, cipherParam);     } } </code></pre> <h4 data-sourcepos="281:1-281:37" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>License 校验类需要的参数</h4> <pre data-sourcepos="283:1-294:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; @Data publicclassLicenseVerifyParam{     privateString subject;     privateString publicAlias;     privateString storePass;     privateString licensePath;     privateString publicKeysStorePath; } </code></pre> <h4 data-sourcepos="296:1-296:30" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>自定义 <code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 13.6px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>KeyStoreParam</code></h4> <pre data-sourcepos="298:1-342:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importde.schlichtherle.license.AbstractKeyStoreParam; importjava.io.IOException; importjava.io.InputStream; importjava.nio.file.Files; importjava.nio.file.Paths; publicclassCustomKeyStoreParamextendsAbstractKeyStoreParam{     privatefinalString storePath;     privatefinalString alias;     privatefinalString storePwd;     privatefinalString keyPwd;     publicCustomKeyStoreParam(Class clazz,String resource,String alias,String storePwd,String keyPwd){         super(clazz, resource);         this.storePath = resource;         this.alias = alias;         this.storePwd = storePwd;         this.keyPwd = keyPwd;     }     @Override     publicStringgetAlias(){         return alias;     }     @Override     publicStringgetStorePwd(){         return storePwd;     }     @Override     publicStringgetKeyPwd(){         return keyPwd;     }     @Override     publicInputStreamgetStream()throwsIOException{         returnFiles.newInputStream(Paths.get(storePath));     } } </code></pre> <h4 data-sourcepos="344:1-344:29" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>LicenseManager 的单例</h4> <pre data-sourcepos="346:1-366:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importde.schlichtherle.license.LicenseManager; importde.schlichtherle.license.LicenseParam; publicclassLicenseManagerHolder{     privatestaticvolatileLicenseManagerLICENSE_MANAGER;     publicstaticLicenseManagergetInstance(LicenseParam param){         if(LICENSE_MANAGER==null){             synchronized(LicenseManagerHolder.class){                 if(LICENSE_MANAGER==null){                     LICENSE_MANAGER=newLicenseManager(param);                 }             }         }         returnLICENSE_MANAGER;     } } </code></pre> <h4 data-sourcepos="368:1-368:32" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>项目启动时安装证书</h4> <h5 data-sourcepos="369:1-369:37" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 0.875rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;><code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 11.9px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>application.properties</code> 配置</h5> <pre data-sourcepos="370:1-375:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;># License 配置 license.subject=license license.publicAlias=myKeyPass123 license.storePass=myStorePass123 </code></pre> <h5 data-sourcepos="377:1-377:30" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 0.875rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;><code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 11.9px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>LicenseCheckRunner</code> 类</h5> <pre data-sourcepos="379:1-418:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.license; importlombok.extern.slf4j.Slf4j; importorg.springframework.beans.factory.annotation.Value; importorg.springframework.boot.ApplicationArguments; importorg.springframework.boot.ApplicationRunner; importorg.springframework.stereotype.Component; @Slf4j @Component publicclassLicenseCheckRunnerimplementsApplicationRunner{     @Value("${license.subject}")     privateString subject;     @Value("${license.publicAlias}")     privateString publicAlias;     @Value("${license.storePass}")     privateString storePass;     @Override     publicvoidrun(ApplicationArguments args)throwsException{         log.info("++++++++ 开始安装证书 ++++++++");         LicenseVerifyParam param =newLicenseVerifyParam();         param.setSubject(subject);         param.setPublicAlias(publicAlias);         param.setStorePass(storePass);         String resourcePath =getClass().getClassLoader().getResource("").getPath();         param.setLicensePath(resourcePath +"license.lic");         param.setPublicKeysStorePath(resourcePath +"publicCerts.keystore");         LicenseVerify licenseVerify =newLicenseVerify();         licenseVerify.install(param);         log.info("++++++++ 证书安装结束 ++++++++");     } } </code></pre> <h4 data-sourcepos="420:1-420:20" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 16px;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>配置拦截器</h4> <h5 data-sourcepos="421:1-421:31" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 0.875rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;><code style="box-sizing: border-box;font-family: SFMono-Regular, Consolas, " liberation mono, menlo, monospace;font-size: 11.9px;padding: 0.2rem 0.4rem;margin: 0px;background-color: rgb(247, 248, 248);color: rgb(9, 132, 79);border-radius: 0.1875rem;>LicenseCheckInterceptor</code></h5> <pre data-sourcepos="423:1-453:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.interceptor; importcom.icoderoad.license.LicenseVerify; importlombok.extern.slf4j.Slf4j; importorg.springframework.web.servlet.HandlerInterceptor; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importjava.util.HashMap; importjava.util.Map; @Slf4j publicclassLicenseCheckInterceptorimplementsHandlerInterceptor{     @Override     publicbooleanpreHandle(HttpServletRequest request,HttpServletResponse response,Object handler)throwsException{         LicenseVerify licenseVerify =newLicenseVerify();         boolean verifyResult = licenseVerify.verify();         if(verifyResult){             returntrue;         }else{             response.setCharacterEncoding("utf-8");             Map<String, String> result =newHashMap<>(1);             result.put("result","您的证书无效，请核查服务器是否取得授权或重新申请证书！");             response.getWriter().write(JSON.toJSONString(result));             returnfalse;         }     } } </code></pre> <h5 data-sourcepos="455:1-455:21" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 0.875rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>注册拦截器</h5> <pre data-sourcepos="457:1-472:3" tabindex="0" style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;margin: 0.5rem 0px;overflow-wrap: normal;padding: 1rem;overflow: auto;line-height: 1.45;background: rgb(247, 248, 248);border-radius: 0.1875rem;color: black;text-align: left;word-spacing: normal;word-break: normal;tab-size: 4;hyphens: none;><code style="white-space:pre-wrap;box-sizing: border-box;font-family: Consolas, Monaco, " andale mono, ubuntu monospace;font-size: 13.6px;padding: 0px;margin: 0px;background-color: initial;color: rgb(9, 132, 79);border-radius: 0.1875rem;background-image: none;background-position: 0% 0%;background-size: auto;background-repeat: repeat;background-attachment: scroll;background-origin: padding-box;background-clip: border-box;text-align: left;word-spacing: normal;word-break: normal;overflow-wrap: normal;tab-size: 4;hyphens: none;border: 0px;display: inline;overflow: visible;line-height: inherit;>package com.icoderoad.config; importcom.icoderoad.interceptor.LicenseCheckInterceptor; importorg.springframework.context.annotation.Configuration; importorg.springframework.web.servlet.config.annotation.InterceptorRegistry; importorg.springframework.web.servlet.config.annotation.WebMvcConfigurer; @Configuration publicclassWebMvcConfigimplementsWebMvcConfigurer{     @Override     publicvoidaddInterceptors(InterceptorRegistry registry){         registry.addInterceptor(newLicenseCheckInterceptor());     } } </code></pre> <h3 data-sourcepos="474:1-474:10" style="box-sizing: border-box;margin-top: 1.5rem;margin-bottom: 1rem;font-weight: 600;line-height: 1.25;font-size: 1.25rem;color: rgb(5, 149, 191);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-style: normal;font-variant-caps: normal;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>总结</h3> <p data-sourcepos="476:1-476:223" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 1rem;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>本文系统性地阐述了在 SpringBoot 项目中实现 License 认证的简洁方案。从背景概述到实现细节，我们深入探讨了如何通过生成密钥对和证书实现高效的 License 校验机制。 <p data-sourcepos="478:1-479:300" style="box-sizing: border-box;margin-top: 0px;margin-bottom: 0px !important;caret-color: rgb(51, 51, 51);color: rgb(51, 51, 51);font-family: -apple-system, BlinkMacSystemFont, " segoe ui, helvetica, arial, sans-serif, apple color emoji, segoe ui emoji;font-size: 16px;font-style: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: auto;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;widows: auto;word-spacing: 0px;-webkit-text-stroke-width: 0px;text-decoration: none;>通过使用 TrueLicense 工具，开发者能够快速生成符合项目需求的证书，而在项目中引入 License 验证功能后，可以有效提升应用的安全性和合规性。此外，本文所介绍的方案灵活性强，适用于多种使用场景，尤其是在复杂的企业内网部署环境中具有显著优势。 未来，您可以根据项目的特定需求，进一步扩展 License 认证功能，例如：绑定硬件信息、增加多级权限控制等，以实现更加精细化的授权管理。希望本篇文章能够为您提供切实可行的技术思路，助力构建专业的 License 认证体系。

GitHub 上非常厉害的 Java Function 代码写法参考

作者：微信小助手

<p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 0px;color: rgb(10, 10, 10);font-family: ui-sans-serif, system-ui, sans-serif, " apple color emoji, segoe ui symbol, noto emoji;font-style: normal;font-variant-ligatures: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: 2;text-align: start;text-indent: 0px;text-transform: none;widows: 2;word-spacing: 0px;-webkit-text-stroke-width: 0px;white-space: normal;background-color: rgb(255, 255, 255);text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial;font-size: 0px;line-height: 0;>  <section style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));color: rgb(10, 10, 10);font-style: normal;font-variant-ligatures: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: 2;text-indent: 0px;text-transform: none;widows: 2;word-spacing: 0px;-webkit-text-stroke-width: 0px;white-space: normal;background-color: rgb(255, 255, 255);text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>在 Java 8 引入的函数式编程支持中，<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, " liberation mono, courier new, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 接口作为最常用的工具之一，广泛应用于各种复杂的场景。今天我们将继续探讨 GitHub 上一些非常厉害的 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 代码写法参考，这些代码在实际项目中解决了各种问题，并展示了 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 的高级技巧。我们将看到一些新的实践，远离前面提到的简单示例，而是探索更具创意和挑战性的应用。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h3 style="box-sizing: border-box;border-width: 0px 0px 1px 4px;border-style: solid solid dashed;border-bottom-color: rgb(0, 152, 116);border-left-color: rgb(0, 152, 116);font-size: 18px;font-weight: bold;margin: 2em 8px 0.75em 0px;text-align: left;line-height: 1.2;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;padding-left: 12px;color: rgb(63, 63, 63);>1. <strong style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-weight: bold;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: inherit;color: rgb(0, 152, 116);><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional</code> 配合使用</h3> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>在很多实际开发中，<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional</code> 用于避免空指针异常（<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>NullPointerException</code>）。将 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 与 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional</code> 配合使用可以帮助我们优雅地处理可空对象，并避免冗长的条件判断。 <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>代码示例：</h4> <pre style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 14px;margin: 10px 8px;color: rgb(171, 178, 191);background: rgb(40, 44, 52);text-align: left;line-height: 1.5;overflow-x: auto;border-radius: 8px;box-shadow: rgba(0, 0, 0.05) 0px inset;padding: !important;> <svg xmlns="http://www.w3.org/2000/svg" version="1.1" x="0px" y="0px" width="45px" height="13px" viewbox="0 0 450 130"> <ellipse cx="50" cy="65" rx="50" ry="52" stroke="rgb(220,60,54)" stroke-width="2" fill="rgb(237,108,96)"></ellipse><ellipse cx="225" cy="65" rx="50" ry="52" stroke="rgb(218,151,33)" stroke-width="2" fill="rgb(247,193,81)"></ellipse><ellipse cx="400" cy="65" rx="50" ry="52" stroke="rgb(27,161,37)" stroke-width="2" fill="rgb(100,200,86)"></ellipse> </svg><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: " fira code, menlo, operator mono, consolas, monaco, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 15px;display: -webkit-box;padding: 0.5em 1em 1em;overflow-x: auto;text-indent: 0px;text-align: left;line-height: 1.75;margin: 0px;white-space: pre-wrap;>import java.util.Optional; import java.util.function.Function; publicclassFunctionWithOptional {     publicstaticvoidmain(String[] args) {         // 定义一个 User 类         classUser {             String name;             int age;             User(String name, int age) {                 this.name = name;                 this.age = age;             }         }         // 使用 Optional 和 Function 提取用户年龄         Function <user, optional<integer>> getAge = user -> Optional.ofNullable(user).map(u -> u.age); </user,>         // 创建一个 User 对象         Useruser=newUser("Alice", 30);         // 使用 Optional 来安全地获取年龄         Optional <integer> age = getAge.apply(user); </integer>         age.ifPresent(a -> System.out.println("User's age: " + a));  // 输出 User's age: 30         // 使用 null 时，返回空 Optional         age = getAge.apply(null);         age.ifPresent(a -> System.out.println("User's age: " + a));  // 不输出任何内容     } }</code></pre> <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>解释：</h4> <ul style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));list-style: none;margin: 0px;padding: 0px 0px 0px 1.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;color: rgb(63, 63, 63); class="list-paddingleft-1"> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>getAge</code> 是一个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code>，它接收 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>User</code> 对象，并使用 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional</code> 包装返回的结果。这样可以优雅地处理空值情况，避免了手动检查 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>null</code>。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • 通过 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>map()</code> 方法，只有在 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>user</code> 非 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>null</code> 时才会提取 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>age</code>，否则返回 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional.empty()</code>，避免了异常的发生。 </section></li> </ul> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>这种方式在链式调用中非常有用，可以高效地避免 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>NullPointerException</code>。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h2 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 19.5px;font-weight: bold;margin: 4em auto 2em;text-align: center;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;display: table;padding: 0.3em 1em;color: rgb(255, 255, 255);background: rgb(0, 152, 116);border-radius: 8px;box-shadow: rgba(0, 0, 0.1) 0px 4px 6px;>2. <strong style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-weight: bold;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: inherit;color: rgb(0, 152, 116);><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 17.55px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 17.55px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Predicate</code> 联合使用进行过滤</h2> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>在处理数据集合时，我们经常需要对数据进行过滤并进行转换，使用 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Predicate</code> 联合能够简洁地实现这一功能。例如，可以先使用 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Predicate</code> 筛选符合条件的数据，再使用 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 转换数据的形式。 <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>代码示例：</h4> <pre style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 14px;margin: 10px 8px;color: rgb(171, 178, 191);background: rgb(40, 44, 52);text-align: left;line-height: 1.5;overflow-x: auto;border-radius: 8px;box-shadow: rgba(0, 0, 0.05) 0px inset;padding: !important;> <svg xmlns="http://www.w3.org/2000/svg" version="1.1" x="0px" y="0px" width="45px" height="13px" viewbox="0 0 450 130"> <ellipse cx="50" cy="65" rx="50" ry="52" stroke="rgb(220,60,54)" stroke-width="2" fill="rgb(237,108,96)"></ellipse><ellipse cx="225" cy="65" rx="50" ry="52" stroke="rgb(218,151,33)" stroke-width="2" fill="rgb(247,193,81)"></ellipse><ellipse cx="400" cy="65" rx="50" ry="52" stroke="rgb(27,161,37)" stroke-width="2" fill="rgb(100,200,86)"></ellipse> </svg><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: " fira code, menlo, operator mono, consolas, monaco, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 15px;display: -webkit-box;padding: 0.5em 1em 1em;overflow-x: auto;text-indent: 0px;text-align: left;line-height: 1.75;margin: 0px;white-space: pre-wrap;>import java.util.List; import java.util.function.Function; import java.util.function.Predicate; import java.util.stream.Collectors; publicclassFunctionWithPredicate {     publicstaticvoidmain(String[] args) {         // 假设我们有一个 User 类         classUser {             String name;             int age;             User(String name, int age) {                 this.name = name;                 this.age = age;             }             @Override             public String toString() {                 return"User{name='" + name + "', age=" + age + "}";             }         }         // 创建一组 User 数据         List <user> users = List.of( </user>             newUser("Alice", 25),             newUser("Bob", 35),             newUser("Charlie", 28),             newUser("David", 40)         );         // 定义一个 Predicate，筛选年龄大于 30 的用户         Predicate <user> isOlderThan30 = user -> user.age >  </user>30;         // 定义一个 Function，提取用户的姓名         Function <user, string> getName = user -> user.name; </user,>         // 筛选年龄大于 30 的用户并提取姓名         List <string> names = users.stream() </string>             .filter(isOlderThan30)  // 使用 Predicate 进行筛选             .map(getName)           // 使用 Function 转换数据             .collect(Collectors.toList());         System.out.println(names);  // 输出 [Bob, David]     } }</code></pre> <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>解释：</h4> <ul style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));list-style: none;margin: 0px;padding: 0px 0px 0px 1.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;color: rgb(63, 63, 63); class="list-paddingleft-1"> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>isOlderThan30</code> 是一个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Predicate</code>，用于判断用户是否年纪大于 30。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>getName</code> 是一个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code>，将 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>User</code> 对象转换为 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>String</code> 类型（即用户的姓名）。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • 通过 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>filter</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>map</code> 的结合，我们能够高效地筛选出符合条件的用户，并转换成所需的数据格式。 </section></li> </ul> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>这种方法让我们能够以更简洁的方式处理集合中的数据，避免了显式的 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>for</code> 循环，提高了代码的可读性和可维护性。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h3 style="box-sizing: border-box;border-width: 0px 0px 1px 4px;border-style: solid solid dashed;border-bottom-color: rgb(0, 152, 116);border-left-color: rgb(0, 152, 116);font-size: 18px;font-weight: bold;margin: 2em 8px 0.75em 0px;text-align: left;line-height: 1.2;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;padding-left: 12px;color: rgb(63, 63, 63);>3. <strong style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-weight: bold;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: inherit;color: rgb(0, 152, 116);><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Consumer</code> 联合处理异步任务</h3> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>异步编程是现代应用中常见的模式，尤其是在处理 I/O 密集型任务时。<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Consumer</code> 可以联合使用，用于处理异步回调中的数据流。 <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>代码示例：</h4> <pre style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 14px;margin: 10px 8px;color: rgb(171, 178, 191);background: rgb(40, 44, 52);text-align: left;line-height: 1.5;overflow-x: auto;border-radius: 8px;box-shadow: rgba(0, 0, 0.05) 0px inset;padding: !important;> <svg xmlns="http://www.w3.org/2000/svg" version="1.1" x="0px" y="0px" width="45px" height="13px" viewbox="0 0 450 130"> <ellipse cx="50" cy="65" rx="50" ry="52" stroke="rgb(220,60,54)" stroke-width="2" fill="rgb(237,108,96)"></ellipse><ellipse cx="225" cy="65" rx="50" ry="52" stroke="rgb(218,151,33)" stroke-width="2" fill="rgb(247,193,81)"></ellipse><ellipse cx="400" cy="65" rx="50" ry="52" stroke="rgb(27,161,37)" stroke-width="2" fill="rgb(100,200,86)"></ellipse> </svg><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: " fira code, menlo, operator mono, consolas, monaco, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 15px;display: -webkit-box;padding: 0.5em 1em 1em;overflow-x: auto;text-indent: 0px;text-align: left;line-height: 1.75;margin: 0px;white-space: pre-wrap;>import java.util.concurrent.CompletableFuture; import java.util.function.Function; import java.util.function.Consumer; publicclassFunctionWithConsumerAsync {     publicstaticvoidmain(String[] args) {         // 假设我们有一个异步任务：获取用户信息         Function <integer, completablefuture<string>> fetchUserInfo = userId ->  </integer,>             CompletableFuture.supplyAsync(() -> "User" + userId);         // 定义一个 Consumer 用于处理异步结果         Consumer <string> printUserInfo = userInfo -> System.out.println( </string>"Fetched user info: " + userInfo);         // 异步获取用户信息并处理         fetchUserInfo.apply(123)             .thenAccept(printUserInfo);  // 使用 Consumer 处理结果     } }</code></pre> <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>解释：</h4> <ul style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));list-style: none;margin: 0px;padding: 0px 0px 0px 1.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;color: rgb(63, 63, 63); class="list-paddingleft-1"> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>fetchUserInfo</code> 是一个异步任务，它返回一个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>CompletableFuture</code>，该异步任务会根据用户 ID 获取用户信息。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>printUserInfo</code> 是一个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Consumer</code>，用于处理异步回调结果，打印用户信息。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • 使用 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>thenAccept()</code> 方法将 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Consumer</code> 应用到异步结果上，这样可以在数据准备好后异步执行处理逻辑。 </section></li> </ul> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>通过这种方式，我们可以清晰地将数据的获取与后续处理分离，使得异步编程变得更加简洁和易于理解。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h3 style="box-sizing: border-box;border-width: 0px 0px 1px 4px;border-style: solid solid dashed;border-bottom-color: rgb(0, 152, 116);border-left-color: rgb(0, 152, 116);font-size: 18px;font-weight: bold;margin: 2em 8px 0.75em 0px;text-align: left;line-height: 1.2;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;padding-left: 12px;color: rgb(63, 63, 63);>4. <strong style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-weight: bold;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: inherit;color: rgb(0, 152, 116);><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 与高阶函数：动态创建多个转换器</h3> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>在一些复杂的应用场景中，我们可能需要根据不同的条件动态创建多个转换器，并将它们组合起来执行。通过高阶函数，我们可以非常灵活地实现这一需求。 <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>代码示例：</h4> <pre style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 14px;margin: 10px 8px;color: rgb(171, 178, 191);background: rgb(40, 44, 52);text-align: left;line-height: 1.5;overflow-x: auto;border-radius: 8px;box-shadow: rgba(0, 0, 0.05) 0px inset;padding: !important;> <svg xmlns="http://www.w3.org/2000/svg" version="1.1" x="0px" y="0px" width="45px" height="13px" viewbox="0 0 450 130"> <ellipse cx="50" cy="65" rx="50" ry="52" stroke="rgb(220,60,54)" stroke-width="2" fill="rgb(237,108,96)"></ellipse><ellipse cx="225" cy="65" rx="50" ry="52" stroke="rgb(218,151,33)" stroke-width="2" fill="rgb(247,193,81)"></ellipse><ellipse cx="400" cy="65" rx="50" ry="52" stroke="rgb(27,161,37)" stroke-width="2" fill="rgb(100,200,86)"></ellipse> </svg><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: " fira code, menlo, operator mono, consolas, monaco, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 15px;display: -webkit-box;padding: 0.5em 1em 1em;overflow-x: auto;text-indent: 0px;text-align: left;line-height: 1.75;margin: 0px;white-space: pre-wrap;>import java.util.function.Function; publicclassHigherOrderFunction {     publicstaticvoidmain(String[] args) {         // 定义一个高阶函数，生成基于某些条件的转换器         Function <string, function<integer, string>> createConverter = condition -> { </string,>             if ("prefix".equals(condition)) {                 return number -> "Prefix_" + number;             } elseif ("suffix".equals(condition)) {                 return number -> number + "_Suffix";             } else {                 return number -> "NoConversion_" + number;             }         };         // 根据不同条件创建转换器         Function <integer, string> prefixConverter = createConverter.apply( </integer,>"prefix");         Function <integer, string> suffixConverter = createConverter.apply( </integer,>"suffix");         // 使用生成的转换器         System.out.println(prefixConverter.apply(123));  // 输出 Prefix_123         System.out.println(suffixConverter.apply(123));  // 输出 123_Suffix     } }</code></pre> <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>解释：</h4> <ul style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));list-style: none;margin: 0px;padding: 0px 0px 0px 1.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;color: rgb(63, 63, 63); class="list-paddingleft-1"> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>createConverter</code> 是一个高阶函数，根据传入的条件动态生成不同的 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code>。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>prefixConverter</code> 和 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>suffixConverter</code> 是基于条件生成的转换器，分别为整数加上前缀或后缀。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • 这种方式让我们能够根据不同的业务需求动态创建转换逻辑，避免了大量的条件判断语句。 </section></li> </ul> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>通过这种高阶函数的技巧，我们可以在更复杂的应用中实现更加灵活和可维护的转换逻辑。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h3 style="box-sizing: border-box;border-width: 0px 0px 1px 4px;border-style: solid solid dashed;border-bottom-color: rgb(0, 152, 116);border-left-color: rgb(0, 152, 116);font-size: 18px;font-weight: bold;margin: 2em 8px 0.75em 0px;text-align: left;line-height: 1.2;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;padding-left: 12px;color: rgb(63, 63, 63);>5. <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 16.2px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 与集合的组合：链式操作</h3> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>链式操作是函数式编程中的一种常见模式，通过将多个 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 组合在一起，可以实现复杂的转换逻辑。这对于处理集合数据非常有用。 <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>代码示例：</h4> <pre style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 14px;margin: 10px 8px;color: rgb(171, 178, 191);background: rgb(40, 44, 52);text-align: left;line-height: 1.5;overflow-x: auto;border-radius: 8px;box-shadow: rgba(0, 0, 0.05) 0px inset;padding: !important;> <svg xmlns="http://www.w3.org/2000/svg" version="1.1" x="0px" y="0px" width="45px" height="13px" viewbox="0 0 450 130"> <ellipse cx="50" cy="65" rx="50" ry="52" stroke="rgb(220,60,54)" stroke-width="2" fill="rgb(237,108,96)"></ellipse><ellipse cx="225" cy="65" rx="50" ry="52" stroke="rgb(218,151,33)" stroke-width="2" fill="rgb(247,193,81)"></ellipse><ellipse cx="400" cy="65" rx="50" ry="52" stroke="rgb(27,161,37)" stroke-width="2" fill="rgb(100,200,86)"></ellipse> </svg><code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: " fira code, menlo, operator mono, consolas, monaco, monospace;font-feature-settings: normal;font-variation-settings: normal;font-size: 15px;display: -webkit-box;padding: 0.5em 1em 1em;overflow-x: auto;text-indent: 0px;text-align: left;line-height: 1.75;margin: 0px;white-space: pre-wrap;>import java.util.List; import java.util.function.Function; import java.util.stream.Collectors; publicclassFunctionChainWithCollections {     publicstaticvoidmain(String[] args) {         // 创建一组用户年龄数据         List <integer> ages = List.of( </integer>25, 30, 35, 40, 45);         // 定义一个 Function，表示年龄到年龄段的转换         Function <integer, string> ageToRange = age -> { </integer,>             if (age < 30) {                 return"Young";             } elseif (age < 40) {                 return"Middle-aged";             } else {                 return"Old";             }         };         // 定义一个 Function，表示将年龄段转换为推荐的健康活动         Function <string, string > rangeToActivity = range -> {              switch  (range) {                  case "Young" :  return "Running" ;                  case "Middle-aged" :  return "Cycling" ;                  case "Old" :  return "Walking" ;                  default :  return "Unknown" ;             }         };          // 使用链式操作处理年龄数据         List <string> activities = ages.stream() </string>             .map(ageToRange)         // 将年龄转换为年龄段             .map(rangeToActivity)    // 将年龄段转换为活动推荐             .collect(Collectors.toList());         System.out.println(activities);   // 输出 [Running, Running, Cycling, Cycling, Walking]     } } </string,></code></pre> <h4 style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-size: 16.5px;font-weight: bold;margin: 2em 8px 0.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;color: rgb(0, 152, 116);>解释：</h4> <ul style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));list-style: none;margin: 0px;padding: 0px 0px 0px 1.5em;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;color: rgb(63, 63, 63); class="list-paddingleft-1"> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>ageToRange</code> 将年龄转换为年龄段（"Young"、"Middle-aged"、"Old"）。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>rangeToActivity</code> 将年龄段转换为健康活动推荐（如 "Running"、"Cycling" 等）。 </section></li> <li style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;text-indent: -1em;display: block;margin: 0.5em 8px;color: rgb(63, 63, 63);> <section> • 通过链式调用，我们能够优雅地将年龄数据转换成健康活动推荐。 </section></li> </ul> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>这种方法利用了 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 的组合特性，使得数据转换变得简洁、直观，并且易于扩展。 <hr style="box-sizing: border-box;border: none;height: 1px;color: inherit;margin: 2em 0px;text-align: left;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, microsoft yahei, arial, sans-serif;font-size: 15px;transform-origin: 0px 0px;transform: scale(1, 0.5);background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0));> <h3 style="box-sizing: border-box;border-width: 0px 0px 1px 4px;border-style: solid solid dashed;border-bottom-color: rgb(0, 152, 116);border-left-color: rgb(0, 152, 116);font-size: 18px;font-weight: bold;margin: 2em 8px 0.75em 0px;text-align: left;line-height: 1.2;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;padding-left: 12px;color: rgb(63, 63, 63);>结语</h3> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 1.5em 8px;text-align: justify;line-height: 1.75;font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-size: 15px;letter-spacing: 0.1em;color: rgb(63, 63, 63);>通过这些不同的 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 使用场景，我们可以看到它的强大功能：从异步处理、懒加载、到与 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Optional</code>、<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Predicate</code> 等接口的结合，<code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 在 Java 开发中有着极其广泛的应用。这些实际的代码示例展示了 <code style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));font-family: -apple-system-font, BlinkMacSystemFont, " helvetica neue, pingfang sc, hiragino sans gb, microsoft yahei ui, yahei, arial, sans-serif;font-feature-settings: normal;font-variation-settings: normal;font-size: 13.5px;text-align: left;line-height: 1.75;color: rgb(221, 17, 68);background: rgba(27, 31, 35, 0.05);padding: 3px 5px;border-radius: 4px;>Function</code> 在复杂场景中的强大潜力，掌握这些技巧后，您将在开发过程中更加得心应手。 </section> <p style="box-sizing: border-box;border-width: 0px;border-style: solid;border-color: hsl(var(--border));margin: 0px;color: rgb(10, 10, 10);font-family: ui-sans-serif, system-ui, sans-serif, " apple color emoji, segoe ui symbol, noto emoji;font-style: normal;font-variant-ligatures: normal;font-variant-caps: normal;font-weight: 400;letter-spacing: normal;orphans: 2;text-align: start;text-indent: 0px;text-transform: none;widows: 2;word-spacing: 0px;-webkit-text-stroke-width: 0px;white-space: normal;background-color: rgb(255, 255, 255);text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial;font-size: 0px;line-height: 0;>  <section> </section> <mp-style-type data-value="3"></mp-style-type>

农银一面：Filter、Interceptor、Spring AOP 的执行顺序

作者：微信小助手

<section data-tool="mdnice编辑器" data-website="https://www.mdnice.com" style="margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 10px;padding-right: 10px;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;font-family: Optima, PingFangSC-regular, serif;font-size: 16px;color: rgb(0, 0, 0);line-height: 1.5em;word-spacing: 0em;letter-spacing: 0em;word-break: break-word;overflow-wrap: break-word;text-align: left;"> <h2 data-tool="mdnice编辑器" style=" margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;height: auto;justify-content: center;line-height: 1.5em;overflow-x: unset;overflow-y: unset; text-align: left;text-shadow: none;transform: none;width: 100%;-webkit-box-reflect: unset; "><span style=" font-size: 22px;border-bottom-color: rgb(119, 48, 152);color: rgb(119, 48, 152);line-height: 1.5em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: 85%;height: auto;align-items: unset;border-top-style: none;border-bottom-style: solid;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: block;font-weight: bold;flex-direction: unset;float: unset;justify-content: unset;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;overflow-x: unset;overflow-y: unset;padding-top: 0px;padding-bottom: 10px;padding-left: 0px;padding-right: 0px; text-align: center;text-indent: 0em;text-shadow: none;transform: none;-webkit-box-reflect: unset; ">引言</h2> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">在我们的日常开发工作中，<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code>（过滤器）、<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code>（拦截器）和 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">AOP</code>（面向切面编程）是非常常用的 3 种请求处理技术。在不同的应用场景中，使用它们都可以在不影响主业务逻辑的前提下为系统增加额外的功能。面试官去问这个问题的时候，一般是想考察求职者的技术深度和对框架机制的理解。本篇我们从 3 者的基本概念及使用来分析解答下这道面试题。 <h2 data-tool="mdnice编辑器" style=" margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;height: auto;justify-content: center;line-height: 1.5em;overflow-x: unset;overflow-y: unset; text-align: left;text-shadow: none;transform: none;width: 100%;-webkit-box-reflect: unset; "><span style=" font-size: 22px;border-bottom-color: rgb(119, 48, 152);color: rgb(119, 48, 152);line-height: 1.5em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: 85%;height: auto;align-items: unset;border-top-style: none;border-bottom-style: solid;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: block;font-weight: bold;flex-direction: unset;float: unset;justify-content: unset;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;overflow-x: unset;overflow-y: unset;padding-top: 0px;padding-bottom: 10px;padding-left: 0px;padding-right: 0px; text-align: center;text-indent: 0em;text-shadow: none;transform: none;-webkit-box-reflect: unset; ">Filter</h2> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">什么是 Filter</h3> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 是 Java <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 规范的一部分，定义在 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">javax.servlet</code> 包中，<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 可以对 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 容器的所有 HTTP 请求（<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HttpServletRequest</code>）和响应（<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HttpServletResponse</code>）进行预处理或后处理操作。例如，在请求到达目标资源之前执行身份验证或设置字符编码，或者在响应返回给客户端前修改其响应内容格式。 <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">Filter 接口</h3> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">package javax.servlet; import java.io.IOException; public interface Filter {     default public void init(FilterConfig filterConfig) throws ServletException {}     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException;     default public void destroy() {} } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">项目中自定义过滤器需实现该接口，接口中的 3 个方法就是 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 的整个生命周期。<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">init()</code>-初始化、<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">doFilter()</code>-执行过滤逻辑、<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">destroy()</code>-销毁。 <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <p style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">init方法</code>：Web 容器在启动时，会触发每个 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 实例的 init 方法调用并传递一个 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">FilterConfig</code> 对象，该配置允许过滤器获取初始化参数以及 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">ServletContext</code> 上下文对象，从而加载任何所需的资源。该方法在 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 的整个生命周期中仅会在初始化时被调用一次。 <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;">该方法如果抛出异常，Web 容器就会认为这个过滤器无法正常工作，因此不会将它加入到过滤器链中，无法提供后续的请求过滤工作。 </blockquote> </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <p style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">doFilter方法</code>：该方法为 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 的核心工作方法，每一次请求都会调用该方法。 <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">FilterChain</code> 接口参数由具体的 Servlet 容器实现并提供。每个过滤器的 doFilter 方法都会接收一个 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">FilterChain</code> 对象作为参数。在这个方法内部，过滤器可以选择： </blockquote> </section></li> <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 直接处理请求/响应。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 调用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">chain.doFilter(request, response)</code> 将请求传递给下一个过滤器或目标资源。 </section></li> </ul> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <p style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">destroy方法</code>：Web 容器在销毁时，会触发每个 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 实例的 destroy 方法调用，清理过滤器所有持有的资源（如内存、文件句柄、线程等）。该方法在 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 的整个生命周期中也仅会执行一次。 </section></li> </ul> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">Filter 的配置使用</h3> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">在 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">SpringBoot</code> 项目中可以使用如下几种配置方式： <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@WebFilter</code> 注解 + <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@ServletComponentScan</code> 注解 </section></li> </ul> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">在过滤器类上使用 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@WebFilter</code> 注解来定义 URL 模式和其他属性 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">package com.example.filter; @WebFilter(urlPatterns = "/*", filterName = "exampleFilter") public class ExampleFilter implements Filter {     @Override     public void init(FilterConfig filterConfig) throws ServletException {         // 初始化逻辑...     }     @Override     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {         // 传递给下一个过滤器或目标资源         chain.doFilter(request, response);     }     @Override     public void destroy() {         // 清理资源...     } } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">在启动类或者任意配置类上加上 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@ServletComponentScan</code> 注解来让 Spring Boot 自动扫描并注册这些过滤器。 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@SpringBootApplication @ServletComponentScan(basePackages = "com.example.filter") // 指定扫描包路径 public class MyApplication {     public static void main(String[] args) {         SpringApplication.run(MyApplication.class, args);     } } </code></pre> <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">FilterRegistrationBean</code> 进行注册 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@Configuration public class FilterConfig {     @Bean     public FilterRegistrationBean <examplefilter>  </examplefilter>customFilterRegistration() {         FilterRegistrationBean <examplefilter> registrationBean =  </examplefilter>new FilterRegistrationBean<>();         ExampleFilter customFilter = new ExampleFilter();         registrationBean.setFilter(customFilter);         registrationBean.addUrlPatterns("/*");         registrationBean.setOrder(1); // 设置过滤器的执行顺序         // 添加初始化参数         registrationBean.addInitParameter("encoding", "UTF-8");         return registrationBean;     } } </code></pre> <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 直接使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@Component</code> 注解：这种方式可以让 Spring 自动将过滤器组件化，默认会应用到所有请求路径。 </section></li> </ul> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@Component public class ExampleFilter implements Filter {     @Override     public void init(FilterConfig filterConfig) throws ServletException {}     @Override     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {         chain.doFilter(request, response);     }     @Override     public void destroy() {} } </code></pre> <h2 data-tool="mdnice编辑器" style=" margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;height: auto;justify-content: center;line-height: 1.5em;overflow-x: unset;overflow-y: unset; text-align: left;text-shadow: none;transform: none;width: 100%;-webkit-box-reflect: unset; "><span style=" font-size: 22px;border-bottom-color: rgb(119, 48, 152);color: rgb(119, 48, 152);line-height: 1.5em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: 85%;height: auto;align-items: unset;border-top-style: none;border-bottom-style: solid;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: block;font-weight: bold;flex-direction: unset;float: unset;justify-content: unset;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;overflow-x: unset;overflow-y: unset;padding-top: 0px;padding-bottom: 10px;padding-left: 0px;padding-right: 0px; text-align: center;text-indent: 0em;text-shadow: none;transform: none;-webkit-box-reflect: unset; ">Interceptor</h2> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">什么是 Interceptor</h3> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 是 Spring MVC 框架的一部分，是位于 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">org.springframework.web.servlet</code> 包中的 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HandlerInterceptor</code> 接口，用于在请求处理之前或之后执行特定逻辑。与 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 不同的是，<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 不依赖于 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 容器，它是 Spring 框架独有的。 <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">HandlerInterceptor 接口</h3> <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">/**  * A HandlerInterceptor gets called before the appropriate HandlerAdapter triggers the execution of the handler itself.  * This mechanism can be used for a large field of preprocessing aspects, e.g. for authorization checks,  * or common handler behavior like locale or theme changes.  * Its main purpose is to allow for factoring out repetitive handler code.  */ public interface HandlerInterceptor {     default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {         return true;     }     default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable ModelAndView modelAndView) throws Exception {     }     default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, @Nullable Exception ex) throws Exception {     } } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">接口注释意思大致是说，<code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HandlerInterceptor</code> 是在通过 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HandlerAdapter</code> 执行查找到的 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">handler</code> 之前被调用，这种机制主要目的是为了减少重复代码，用于大量的程序预处理工作，比如授权检查等。 <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">preHandle方法</code>：在 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">controller</code> 方法调用之前，按照 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 链<strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">顺序执行，进行权限检查等请求前处理操作。 <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;">如果该方法返回了 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">false</code>，那么不仅当前 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;height: auto;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 会终止执行，整个拦截器链都会被终止。 </blockquote> </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">postHandle方法</code>：在 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">controller</code> 方法调用之后返回 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">ModelAndView</code> 之前执行，与 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">preHandle</code> 不同的是，<code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">postHandle</code> 是按照<code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 链<strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">逆序执行的。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">afterCompletion方法</code>：在整个请求完成后调用，通常用于资源清理或日志记录。 </section></li> </ul> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">执行顺序：<img class="rich_pages wxw-img" data-imgfileid="100003274" src="/upload/f35b1a3bf81f30cdc9cfb98e05b73b18.png" data-type="png" style="display: block;margin-top: 0px;margin-right: auto;margin-bottom: 0px;margin-left: auto;max-width: 100%;"> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">下面我们通过 Spring MVC 在实际分发处理请求时的源码具体看下 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 的执行情况（源码出自 spring-framework-5.0.x）： <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exceptio {     // 此处用 processedRequest 接收了用户的 request 请求     HttpServletRequest processedRequest = request;     // HandlerExecutionChain 局部变量     HandlerExecutionChain mappedHandler = null;     // 标记一下是否解析了文件类型的数据，如果有最终需要清理操作     boolean multipartRequestParsed = false;     WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);     try {         // ModelAndView 局部变量         ModelAndView mv = null;         // 处理异常局部变量         Exception dispatchException = null;         try {             /**              * 判断一下是否是文件上传请求。              * 如果请求是 POST 请求，并且 Context-Type 是以 multipart/ 开头的就认为是文件上传的请求。              * 需要注意的是，若是这里被认定为文件上传请求，processedRequest 和 request 将不再指向同一对象              * 这里返回的是 MultipartHttpServletRequest。              */             processedRequest = checkMultipart(request);             // 两个请求不再相同，进行文件上传标记，用于后续清理操作             multipartRequestParsed = (processedRequest != request);             /**              * 向 HandlerMapping 请求查找 HandlerExecutionChain              * 找到一个处理器，如果没有找到对应的处理类的话，这里通常会返回404。              */             mappedHandler = getHandler(processedRequest);             // 如果没找到对应的处理器，则抛出异常             // 相信大家都见过 'No mapping for GET /xxxx'，就是这里抛出的             if (mappedHandler == null) {                 noHandlerFound(processedRequest, response);                 return;             }             // 根据查找到的 Handler 请求查找能够进行处理的 HandlerAdapter             HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());             // 判断自上次请求后是否有修改，没有修改直接返回响应             // 如果是GET请求，且内容没有变化的话，就直接返回             String method = request.getMethod();             boolean isGet = "GET".equals(method);             if (isGet || "HEAD".equals(method)) {                 long lastModified = ha.getLastModified(request, mappedHandler.getHandler());                 if (log.isDebugEnabled()) {                     log.debug("Last-Modified value for [" + getRequestUri(request) + "] is: " + lastModified);                 }                 if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {                     return;                 }             }             /**              * <<<<<<<<<这里到了我们本节内容，拦截器的执行了>>>>>>>>>              * 这里通过 applyPreHandle 方法，按顺序依次执行 HandlerInterceptor 的 preHandle 方法              * 可以看到，如果任一 HandlerInterceptor 的 preHandle 方法返回了 false，则整个拦截器连              * 不再继续进行处理。              */             if (!mappedHandler.applyPreHandle(processedRequest, response)) {                 return;             }             /**              * 通过 HandlerAdapter 执行查找到的 handler              * 这里真正执行我们 controller 中的方法逻辑，返回一个 ModelAndView              */             mv = ha.handle(processedRequest, response, mappedHandler.getHandler());             /**              * 检查是否已经开始处理并发请求，如果并发处理已经开始，那么当前的请求线程就可以返回了，而不会等待异步操              * 作的结果，也就不会再执行拦截器 PostHandle 之类的操作了。              */             if (asyncManager.isConcurrentHandlingStarted()) {                 return;             }             // 如果我们没有设置 viewName，就采用默认的，否则采用我们自己的             applyDefaultViewName(processedRequest, mv);             // <<<<<<<<< 这里，通过 applyPostHandle 逆序执行 HandlerInterceptor 的 postHandle 方法>>>>>>>>>             mappedHandler.applyPostHandle(processedRequest, response, mv);         }         catch (Exception ex) {             dispatchException = ex;         }         catch (Throwable err) {             // As of 4.3, we're processing Errors thrown from handler methods as well,             // making them available for @ExceptionHandler methods and other scenarios.             dispatchException = new NestedServletException("Handler dispatch failed", err);         }         // 渲染视图填充 Model，如果有异常渲染异常页面         processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);     }     catch (Exception ex) {         // 如果有异常按倒序执行所有 HandlerInterceptor 的 afterCompletion 方法         triggerAfterCompletion(processedRequest, response, mappedHandler, ex);     }     catch (Throwable err) {         // 如果有异常按倒序执行所有 HandlerInterceptor 的 afterCompletion 方法         triggerAfterCompletion(processedRequest, response, mappedHandler,                 new NestedServletException("Handler processing failed", err));     }     finally {         if (asyncManager.isConcurrentHandlingStarted()) {             // Instead of postHandle and afterCompletion             if (mappedHandler != null) {                 // 倒序执行所有 HandlerInterceptor 的 afterCompletion 方法                 mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);             }         }         else {             // Clean up any resources used by a multipart request.             if (multipartRequestParsed) {                 // 如果请求包含文件类型的数据则进行相关清理工作                 cleanupMultipart(processedRequest);             }         }     } } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">上述源码中，其实不仅仅是拦截器的执行顺序了，而是 Spring MVC 处理客户端请求的整个过程。如下图，可以很直观的看出拦截器的执行时机与顺序。 <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100003276" src="/upload/2453abb72c876e15ed9de83ddccc013d.jpg" data-type="jpeg" style="display: block;margin-top: 0px;margin-right: auto;margin-bottom: 0px;margin-left: auto;max-width: 100%;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> <figcaption style="color: rgb(136, 136, 136);font-size: 14px;line-height: 1.5em;letter-spacing: 0em;text-align: center;font-weight: normal;margin-top: 5px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"> 图片来源于网络，侵权请联系删除 </figcaption> </figure> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">Interceptor 的配置使用</h3> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">自定义拦截器，实现 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">HandlerInterceptor</code> 接口 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">public class MyInterceptor implements HandlerInterceptor {     @Override     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {         // 在这里添加拦截逻辑，例如身份验证或日志记录         System.out.println("MyInterceptor preHandle: " + request.getRequestURI());         return true; // 返回 true 继续处理请求，返回 false 中断请求     }     @Override     public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {         // 在视图渲染之前执行的逻辑         System.out.println("MyInterceptor postHandle: " + request.getRequestURI());     }     @Override     public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {         // 请求完成后的逻辑，比如资源清理         System.out.println("MyInterceptor afterCompletion: " + request.getRequestURI());     } } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">实现 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">WebMvcConfigurer</code> 接口并重写 <code style="color: rgb(150, 84, 181);font-size: 14px;line-height: 1.8em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">addInterceptors</code> 方法，将拦截器注册到 Spring MVC 的拦截器链中 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@Configuration public class WebConfig implements WebMvcConfigurer {     @Override     public void addInterceptors(InterceptorRegistry registry) {         // 添加拦截器，并指定拦截路径模式         registry.addInterceptor(new MyInterceptor())                 .addPathPatterns("/**") // 拦截所有路径                 .excludePathPatterns("/static/**", "/login", "/register"); // 排除静态资源和某些 URL     } } </code></pre> <h2 data-tool="mdnice编辑器" style=" margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;height: auto;justify-content: center;line-height: 1.5em;overflow-x: unset;overflow-y: unset; text-align: left;text-shadow: none;transform: none;width: 100%;-webkit-box-reflect: unset; "><span style=" font-size: 22px;border-bottom-color: rgb(119, 48, 152);color: rgb(119, 48, 152);line-height: 1.5em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: 85%;height: auto;align-items: unset;border-top-style: none;border-bottom-style: solid;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: block;font-weight: bold;flex-direction: unset;float: unset;justify-content: unset;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;overflow-x: unset;overflow-y: unset;padding-top: 0px;padding-bottom: 10px;padding-left: 0px;padding-right: 0px; text-align: center;text-indent: 0em;text-shadow: none;transform: none;-webkit-box-reflect: unset; ">AOP（Aspect-Oriented Programming）</h2> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">什么是 AOP</h3> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">AOP（Aspect-Oriented Programming），即面向切面编程，是一种编程范式，目的是通过分离横切关注点（如事务管理、日志记录）来提高代码的模块化程度。AOP 允许开发者定义“切面”（Aspects），通过这些切面可以在不改变业务逻辑的情况下增强现有业务功能。 <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;">AOP 是一种编程思想，Spring AOP 是 Spring 框架提供的 AOP 实现。 </blockquote> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">AOP 核心概念</h3> <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">切面（Aspect）：一个模块化的特殊类，包含通知和切入点，用来实现特定的横切逻辑。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">通知（Advice）：在特定连接点（Join Point）执行的动作，例如前置通知（在目标方法调用之前执行的通知）。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">连接点（Join Point）：程程序执行过程中的一个点，例如方法调用或异常抛出的地方。在 Spring AOP 中，连接点指的是应用程序中所有可能被拦截的方法执行点。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">切入点（Pointcut）：用于匹配连接点的表达式，决定了哪些连接点会应用切面的通知。Spring AOP 使用 AspectJ 的切入点表达式语言。例如：<code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@Pointcut("execution(* com.example.service..*.*(..))")</code> </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">引入（Introduction）：为现有的类添加新方法或属性的能力。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">目标对象（Target Object）：目标对象是指被一个或多个切面所通知的对象，也就是需要对其方法调用进行增强的对象。使用 AOP 时，这些对象会被代理，以便可以在它们的方法调用前后插入额外的行为。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">代理（Proxy）：由 AOP 框架创建的对象，用来实现对目标对象的增强。有两种主要类型的 AOP 代理：JDK 动态代理和 CGLIB 代理。 </section></li> </ul> <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;">Spring AOP 如何创建代理： <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 默认情况下，如果目标对象实现了至少一个接口，Spring AOP 将优先选择 JDK 动态代理。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 如果目标对象没有实现任何接口，则会自动切换到 CGLIB 代理。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> 如果要强制使用 CGLIB 代理，可以在启动类或配置类上添加 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@EnableAspectJAutoProxy(proxyTargetClass = true)</code> 注解即可。 </section></li> </ul> </blockquote> <h3 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;">Spring AOP 的配置使用</h3> <h4 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: block;">Spring AOP 的使用步骤</h4> <ol style="list-style-type: decimal;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">启用 AOP 支持：在启动类或任意配置类上添加 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@EnableAspectJAutoProxy</code> 注解。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">定义切面（Aspect）：创建一个类，使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@Aspect</code> 注解来标记这个类为一个切面，并使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@Component</code> 注解让 Spring 管理这个 Bean。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">指定切入点（Pointcut）：使用 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">@Pointcut</code> 注解加 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">AspectJ</code> 表达式定义切入点。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">定义通知（Advice）：定义一个通知，在特定连接点时执行特定逻辑。 </section></li> </ol> <blockquote style="margin-top: 20px;margin-bottom: 20px;margin-left: 0px;margin-right: 0px;padding-top: 10px;padding-bottom: 10px;padding-left: 20px;padding-right: 10px;border-top-style: none;border-bottom-style: none;border-left-style: solid;border-right-style: solid;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 1px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgb(150, 84, 181);border-right-color: rgb(150, 84, 181);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;background-attachment: scroll;background-clip: border-box;background-color: rgb(251, 249, 253);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;display: block;overflow-x: auto;overflow-y: auto;"> <p style="text-indent: 0em;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;margin-top: 0px;margin-right: 0px;margin-bottom: 0px;margin-left: 0px;">Spring 提供的通知类型有如下几种： <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">@Before（前置通知）：前置通知是在目标方法调用 <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">之前 执行的通知。无论目标方法是否抛出异常或正常返回，前置通知都会被执行。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">@AfterReturning（后置返回通知）：后置返回通知是在目标方法 <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">成功返回后 执行的通知。只有当目标方法没有抛出异常时，才会触发该通知。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">@AfterThrowing（抛出异常通知）：抛出异常通知是在目标方法 <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">抛出异常后 执行的通知。它只会在方法抛出指定类型的异常时触发。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">@Around（环绕通知）：环绕通知是最强大的一种通知类型，它包围了目标方法的调用。你可以完全控制方法的执行，包括决定是否继续执行方法以及如何处理返回值或异常。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">@After（后置最终通知）：后置最终通知是在目标方法 <strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">完成之后 执行的通知，不论方法是正常结束还是因为异常而终止。 </section></li> </ul> </blockquote> <h4 data-tool="mdnice编辑器" style="margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: block;">Spring AOP 使用示例</h4> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">启用 AOP 支持 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@SpringBootApplication @EnableAspectJAutoProxy public class MyApp {     public static void main(String[] args) {         SpringApplication.run(MyApp.class, args);     } } </code></pre> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">定义切面类 <pre data-tool="mdnice编辑器" style="border-radius: 5px;box-shadow: rgba(0, 0, 0, 0.55) 0px 2px 10px;text-align: left;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;"><span data-cacheurl="" data-remoteid="" style="display: block;background: none;height: 30px;width: 100%;background-size: 40px;background-repeat: no-repeat;background-color: #282c34;margin-bottom: -7px;border-radius: 5px;background-position: 10px 10px;background-image: url(" https: mmbiz.qpic.cn mmbiz_svg k0ue4mipav882cnbmffjvlrxfiaoyowabg1n9gndbfbyylu3av0epdc78k5wnsukhhozztyffw9mdqxuoquchp80rlmqpmiibl 640?wx_fmt="svg&from=appmsg");""><code style="overflow-x: auto;padding: 16px;color: #abb2bf;padding-top: 15px;background: #282c34;border-radius: 5px;display: -webkit-box;font-family: Consolas, Monaco, Menlo, monospace;font-size: 12px;">@Slf4j @Aspect @Component public class AllAdviceAspect {     // 定义切入点，匹配 service 包下的所有方法     @Pointcut("execution(* com.example.service..*.*(..))")     public void serviceLayerExecution() {}     // 前置通知，在方法调用前打印日志     @Before("serviceLayerExecution()")     public void logBefore(JoinPoint joinPoint) {         log.info("Before method execution: {}", joinPoint.getSignature().getName());     }     // 后置返回通知，在方法成功返回后打印日志     @AfterReturning(pointcut = "serviceLayerExecution()", returning = "result")     public void logAfterReturning(JoinPoint joinPoint, Object result) {         log.info("Method returned successfully: {}, Result: {}", joinPoint.getSignature().getName(), result);     }     // 抛出异常通知，在方法抛出异常后打印日志     @AfterThrowing(pointcut = "serviceLayerExecution()", throwing = "ex")     public void logAfterThrowing(JoinPoint joinPoint, Exception ex) {         log.error("An exception was thrown in {}: {}", joinPoint.getSignature().getName(), ex.getMessage());     }     // 后置最终通知，在方法完成之后打印日志，无论是否抛出异常     @After("serviceLayerExecution()")     public void logAfter(JoinPoint joinPoint) {         log.info("After method execution: {}", joinPoint.getSignature().getName());     }     // 环绕通知，包围方法调用，控制方法执行流程     @Around("serviceLayerExecution()")     public Object logAround(ProceedingJoinPoint pjp) throws Throwable {         log.info("Starting around advice for method: {}", pjp.getSignature().getName());         long start = System.currentTimeMillis();         try {             // 执行目标方法             Object result = pjp.proceed();             log.info("Method {} took {} ms to execute", pjp.getSignature().getName(), System.currentTimeMillis() - start);             return result;         } catch (Throwable e) {             log.error("Error during method execution: {}", e.getMessage());             throw e; // 重新抛出异常以便后续处理         } finally {             log.info("Ending around advice for method: {}", pjp.getSignature().getName());         }     } } </code></pre> <h2 data-tool="mdnice编辑器" style=" margin-top: 30px;margin-bottom: 15px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;align-items: unset;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: flex;flex-direction: unset;float: unset;height: auto;justify-content: center;line-height: 1.5em;overflow-x: unset;overflow-y: unset; text-align: left;text-shadow: none;transform: none;width: 100%;-webkit-box-reflect: unset; "><span style=" font-size: 22px;border-bottom-color: rgb(119, 48, 152);color: rgb(119, 48, 152);line-height: 1.5em;letter-spacing: 0em;background-attachment: scroll;background-clip: border-box;background-color: unset;background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: 85%;height: auto;align-items: unset;border-top-style: none;border-bottom-style: solid;border-left-style: none;border-right-style: none;border-top-width: 1px;border-bottom-width: 1px;border-left-width: 1px;border-right-width: 1px;border-top-color: rgb(0, 0, 0);border-left-color: rgb(0, 0, 0);border-right-color: rgb(0, 0, 0);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-left-radius: 0px;border-bottom-right-radius: 0px;box-shadow: none;display: block;font-weight: bold;flex-direction: unset;float: unset;justify-content: unset;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;overflow-x: unset;overflow-y: unset;padding-top: 0px;padding-bottom: 10px;padding-left: 0px;padding-right: 0px; text-align: center;text-indent: 0em;text-shadow: none;transform: none;-webkit-box-reflect: unset; ">三者之间对比</h2> <ul style="list-style-type: disc;margin-top: 8px;margin-bottom: 8px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 25px;padding-right: 0px;color: rgb(0, 0, 0);" class="list-paddingleft-1"> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 是 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Java Servlet</code> 规范的一部分，它工作在 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 容器层面，是 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 容器级别的，适用于所有进入应用的 HTTP 请求。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 是 Spring MVC 框架提供的一种请求处理机制，是属于框架级别的。通过 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 章节的源码可以看出，<code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 工作在 Spring MVC 分发处理请求时，而分发请求的类是 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">DispatcherServlet</code>，它是一个 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code>，根据 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 规范，<code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 是先于 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Servlet</code> 执行的。所以 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Filter</code> 要比 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 优先执行。 </section></li> <li> <section style="margin-top: 5px;margin-bottom: 5px;color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;font-weight: normal;"> Spring AOP 是 Spring 框架提供的面向切面编程的支持，允许我们在不改变原有业务逻辑的前提下，集中处理横切关注点。它的执行时机是在特定的连接点，也就是请求已经到了我们 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">controller</code> 中的某个方法时才会触发，而 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 在执行查找到的 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">handler</code> 之前就已经被调用了，所以 <code style="background-attachment: scroll;background-clip: border-box;background-color: rgba(27, 31, 35, 0.05);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 2px;margin-right: 2px;padding-top: 2px;padding-bottom: 2px;padding-left: 4px;padding-right: 4px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgb(0, 0, 0);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 4px;border-top-right-radius: 4px;border-bottom-right-radius: 4px;border-bottom-left-radius: 4px;overflow-wrap: break-word;font-family: 'Operator Mono', Consolas, Monaco, Menlo, monospace;word-break: break-all;">Interceptor</code> 要先于 Spring AOP 执行。 </section></li> </ul> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;"><strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">执行顺序如下图： <figure data-tool="mdnice编辑器" style="margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;display: flex;flex-direction: column;justify-content: center;align-items: center;"> <img class="rich_pages wxw-img" data-imgfileid="100003275" src="/upload/b3d9b349c7e734c17c83705218cc47a9.png" data-type="png" style="display: block;margin-top: 0px;margin-right: auto;margin-bottom: 0px;margin-left: auto;max-width: 100%;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;object-fit: fill;box-shadow: rgba(0, 0, 0, 0) 0px 0px 0px 0px;"> </figure> <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">本篇主要基于 SpringBoot 介绍了过滤器、拦截器和 Spring AOP，通过学习其基本知识了解到了它们工作时的执行顺序。实际上，其实无论是过滤器还是拦截器，都可以被视为 AOP 思想的具体实现形式，尽管它们各自工作在不同的层次上。 <p data-tool="mdnice编辑器" style="color: rgb(90, 90, 90);font-size: 15px;line-height: 1.8em;letter-spacing: 0.02em;text-align: left;text-indent: 0em;margin-top: 10px;margin-bottom: 10px;margin-left: 0px;margin-right: 0px;padding-top: 8px;padding-bottom: 8px;padding-left: 0px;padding-right: 0px;">您的鼓励对我持续创作非常关键，如果本文对您有帮助，请记得<strong style="color: rgb(0, 0, 0);font-weight: bold;background-attachment: scroll;background-clip: border-box;background-color: rgba(0, 0, 0, 0);background-image: none;background-origin: padding-box;background-position-x: 0%;background-position-y: 0%;background-repeat: no-repeat;background-size: auto;width: auto;height: auto;margin-top: 0px;margin-bottom: 0px;margin-left: 0px;margin-right: 0px;padding-top: 0px;padding-bottom: 0px;padding-left: 0px;padding-right: 0px;border-top-style: none;border-bottom-style: none;border-left-style: none;border-right-style: none;border-top-width: 3px;border-bottom-width: 3px;border-left-width: 3px;border-right-width: 3px;border-top-color: rgba(0, 0, 0, 0.4);border-bottom-color: rgba(0, 0, 0, 0.4);border-left-color: rgba(0, 0, 0, 0.4);border-right-color: rgba(0, 0, 0, 0.4);border-top-left-radius: 0px;border-top-right-radius: 0px;border-bottom-right-radius: 0px;border-bottom-left-radius: 0px;">点赞、分享、在看哦~~~谢谢！ </section> <mp-style-type data-value="3"></mp-style-type>

Flinkcdc和Canal哪个性能更好，你测试对比了吗？你会选择用哪个？

作者：微信小助手

<section> 结论： </section> <section>      解析同步效率：Flinkcdc完胜（遥遥领先！！！！！） </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang=""><code> Flinkcdc > Canal</code></pre> </section> <section>     选择用哪个？ </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang=""><code>推荐：Flinkcdc</code></pre> </section> <section> </section> <section> 一、测试对比： </section> <section> 1.1、版本对比： </section> <section> <code>1、Flinkcdc</code> </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="xml"><code><dependency>    </code><code>  <groupId>com.ververicagroupId>    </code><code>  <artifactId>flink-connector-mysql-cdcartifactId>    </code><code>  <version>2.4.0version></code><code>dependency></code></pre> </section> <section> 2、canal： </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang=""><code>canal.deployer-1.1.5.tar.gz</code></pre> </section> <section> 1.2、数据总量： </section> <section>     在MySQL数据库中导入数据量为 1.5亿数据（涉及200多个表），4个小时导入完成。Flinkcdc和Canal都什么时候同步完成了？ </section> <section> 注：Flinkcdc 和Canal同时接入同一个库来数据解析并同步数据。 </section> <section> 前提条件： </section> <section> 数据：1.5亿 </section> <section> 导入时长：4个小时 </section> <section> 1、Flinkcdc： </section> <section> 解析同步时长：6个小时 </section> <section style="text-align: center;" nodeleaf=""> <img class="rich_pages wxw-img" data-imgfileid="100001548" data-ratio="0.2644281217208814" data-s="300,640" src="/upload/ad62b4b758fdf6057dc80640c3f9439f.png" data-type="png" data-w="953" type="block"> </section> <section> 2、Canal： </section> <section> 解析同步时长：13个小时 </section> <section style="text-align: center;" nodeleaf=""> <img class="rich_pages wxw-img" data-imgfileid="100001549" data-ratio="0.24310520939734423" data-s="300,640" src="/upload/2af47fa04c74e7642b1d642e84339e25.png" data-type="png" data-w="979" type="block"> </section> <section> 结论： </section> <section>      解析同步效率：Flinkcdc 完胜 </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang=""><code> Flinkcdc > Canal</code></pre> </section> <section> </section> <section> 1.3、如果现有Canal需升级为Flinkcdc？怎么弄了？(生产环境) </section> <section> 结论： </section> <section> 1、数据格式转换： </section> <section>       将Flinkcdc的数据格式转换成Canal数据格式。其余都不用变。 </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang=""><code> FlinkCdcEvent  -> CanalEvent</code></pre> </section> <section> 2、数据解析后都是Json： </section> <section> </section> <section>         记得用Gson转换。fastjson有坑，不建议用. </section> <section>         记得用Gson转换。fastjson有坑，不建议用. </section> <section>         记得用Gson转换。fastjson有坑，不建议用. </section> <section> </section> <section> 1.4、Flinkcdc及Canal数据格式对比： </section> <section> 1、CanalEvent： </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="typescript"><code>import java.util.List;</code><code>import java.util.Map;</code><code>public class CanalEvent {</code><code>    private List<Map<String, String>> data;</code><code>    private String database;</code><code>    private long es;</code><code>    private long id;</code><code>    private boolean isDdl;</code><code>    private Map<String, String> mysqlType;</code><code>    private List<Map<String, String>> old;</code><code>    private List<String> pkNames;</code><code>    private String sql;</code><code>    private Map<String, Integer> sqlType;</code><code>    private String table;</code><code>    private long ts;</code><code>    private String type;</code><code>    </code><code>    // Getters and setters</code><code>    // toString</code><code>    ...</code><code>}</code></pre> </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="javascript"><code>{</code><code>  "data": [</code><code>    {</code><code>      "id": "G00002",</code><code>      "name": "阿龙大数据",</code><code>      "province_id": "32",</code><code>      "province": "江苏省",</code><code>      "city_id": "3201",</code><code>      "city": "南京市",</code><code>      "district_id": "320114",</code><code>      "district": "雨花台区",</code><code>      "address": "科创城23222333444",</code><code>      "logo_url": "http://along/icon_112.png",</code><code>      "slogan": "欢迎",</code><code>      "credit_code": "2343243",</code><code>      "master_name": "阿龙",</code><code>      "master_idcard": "532524199911304246",</code><code>      "power_group_id": "9996",</code><code>      "opt_time": "2021-10-19 17:41:57",</code><code>      "add_user_id": "132",</code><code>      "add_user_name": "测试",</code><code>      "add_time": "2020-07-27 13:59:34",</code><code>      "email": "123456@qq.com",</code><code>      "master_wechat": null,</code><code>      "service_phone": "13232323232",</code><code>      "max_shop_num": "5",</code><code>      "pay_mode": null,</code><code>      "business_license": "https://image/MXVSeb7Pv4r1f1346237770562140.jpg",</code><code>      "idcard_front": "https://image/13uty9yyvrlvWb346237808202139.png",</code><code>      "idcard_back": "https:///image/5uA7IblI6r1zoW346237778042125.png",</code><code>      "cloud_shop_state": "0",</code><code>      "expiration_time": null,</code><code>      "version_id": null,</code><code>      "company_type": "0",</code><code>      "company_property": "1",</code><code>      "main_sell": null,</code><code>      "introduction": null,</code><code>      "contact_name": null,</code><code>      "contact_phone": null,</code><code>      "certification_name": "阿龙大数据",</code><code>      "is_test": null,</code><code>      "login_account": null,</code><code>      "delete_at": "0",</code><code>      "self_invitation_code": "IN6501"</code><code>    }</code><code>  ],</code><code>  "database": "test",</code><code>  "es": 1669010586000,</code><code>  "id": 8150,</code><code>  "isDdl": false,</code><code>  "mysqlType": {</code><code>    "id": "varchar(32)",</code><code>    "name": "varchar(64)",</code><code>    "province_id": "int(6)",</code><code>    "province": "varchar(32)",</code><code>    "city_id": "int(6)",</code><code>    "city": "varchar(32)",</code><code>    "district_id": "int(6)",</code><code>    "district": "varchar(64)",</code><code>    "address": "varchar(128)",</code><code>    "logo_url": "varchar(500)",</code><code>    "slogan": "varchar(255)",</code><code>    "credit_code": "varchar(18)",</code><code>    "master_name": "varchar(16)",</code><code>    "master_idcard": "varchar(18)",</code><code>    "power_group_id": "bigint(20)",</code><code>    "opt_time": "datetime",</code><code>    "add_user_id": "varchar(32)",</code><code>    "add_user_name": "varchar(32)",</code><code>    "add_time": "datetime",</code><code>    "email": "varchar(255)",</code><code>    "master_wechat": "varchar(255)",</code><code>    "service_phone": "varchar(32)",</code><code>    "max_shop_num": "int(11)",</code><code>    "pay_mode": "int(1)",</code><code>    "business_license": "varchar(128)",</code><code>    "idcard_front": "varchar(128)",</code><code>    "idcard_back": "varchar(128)",</code><code>    "cloud_shop_state": "int(1)",</code><code>    "expiration_time": "datetime",</code><code>    "version_id": "bigint(20)",</code><code>    "company_type": "tinyint(2)",</code><code>    "company_property": "int(2)",</code><code>    "main_sell": "varchar(200)",</code><code>    "introduction": "varchar(512)",</code><code>    "contact_name": "varchar(32)",</code><code>    "contact_phone": "varchar(11)",</code><code>    "certification_name": "varchar(64)",</code><code>    "is_test": "int(1)",</code><code>    "login_account": "varchar(50)",</code><code>    "delete_at": "bigint(14)",</code><code>    "self_invitation_code": "char(6)"</code><code>  },</code><code>  "old": [</code><code>    {</code><code>      "address": "北京"</code><code>    }</code><code>  ],</code><code>  "pkNames": [</code><code>    "id"</code><code>  ],</code><code>  "sql": "",</code><code>  "sqlType": {</code><code>    "id": 12,</code><code>    "name": 12,</code><code>    "province_id": 4,</code><code>    "province": 12,</code><code>    "city_id": 4,</code><code>    "city": 12,</code><code>    "district_id": 4,</code><code>    "district": 12,</code><code>    "address": 12,</code><code>    "logo_url": 12,</code><code>    "slogan": 12,</code><code>    "credit_code": 12,</code><code>    "master_name": 12,</code><code>    "master_idcard": 12,</code><code>    "power_group_id": -5,</code><code>    "opt_time": 93,</code><code>    "add_user_id": 12,</code><code>    "add_user_name": 12,</code><code>    "add_time": 93,</code><code>    "email": 12,</code><code>    "master_wechat": 12,</code><code>    "service_phone": 12,</code><code>    "max_shop_num": 4,</code><code>    "pay_mode": 4,</code><code>    "business_license": 12,</code><code>    "idcard_front": 12,</code><code>    "idcard_back": 12,</code><code>    "cloud_shop_state": 4,</code><code>    "expiration_time": 93,</code><code>    "version_id": -5,</code><code>    "company_type": -6,</code><code>    "company_property": 4,</code><code>    "main_sell": 12,</code><code>    "introduction": 12,</code><code>    "contact_name": 12,</code><code>    "contact_phone": 12,</code><code>    "certification_name": 12,</code><code>    "is_test": 4,</code><code>    "login_account": 12,</code><code>    "delete_at": -5,</code><code>    "self_invitation_code": 1</code><code>  },</code><code>  "table": "company",</code><code>  "ts": 1669010468134,</code><code>  "type": "UPDATE"</code><code>}</code></pre> </section> <section> </section> <section> 2、FlinkCdcEvent： </section> <section class="code-snippet__fix code-snippet__js"> <ul class="code-snippet__line-index code-snippet__js"> </ul> <pre class="code-snippet__js" data-lang="javascript"><code>{</code><code>  "before": {</code><code>    "id": "PF1784570096901248",</code><code>    "pay_order_no": null,</code><code>    "out_no": "J1784570080435328",</code><code>    "title": "充值办卡",</code><code>    "from_user_id": "PG11111",</code><code>    "from_account_id": "1286009802396288",</code><code>    "user_id": "BO1707796995184000",</code><code>    "account_id": "1707895210106496",</code><code>    "amount": 13400,</code><code>    "profit_state": 1,</code><code>    "profit_time": 1686758315000,</code><code>    "refund_state": 0,</code><code>    "refund_time": null,</code><code>    "add_time": 1686758315000,</code><code>    "remark": "充值办卡",</code><code>    "acct_circle": "PG11111",</code><code>    "user_type": 92,</code><code>    "from_user_type": 90,</code><code>    "company_id": "PG11111",</code><code>    "profit_mode": 1,</code><code>    "type": 2,</code><code>    "parent_id": null,</code><code>    "oc_profit_id": "1784570096901248",</code><code>    "keep_account_from_user_id": null,</code><code>    "keep_account_from_bm_user_id": null,</code><code>    "keep_account_user_id": null,</code><code>    "keep_account_bm_user_id": null,</code><code>    "biz_company_id": "PG11111"</code><code>  },</code><code>  "after": {</code><code>    "id": "PF1784570096901248",</code><code>    "pay_order_no": null,</code><code>    "out_no": "J1784570080435328",</code><code>    "title": "充值办卡",</code><code>    "from_user_id": "PG11111",</code><code>    "from_account_id": "1286009802396288",</code><code>    "user_id": "BO1707796995184000",</code><code>    "account_id": "1707895210106496",</code><code>    "amount": 13400,</code><code>    "profit_state": 1,</code><code>    "profit_time": 1686758315000,</code><code>    "refund_state": 0,</code><code>    "refund_time": null,</code><code>    "add_time": 1686758315000,</code><code>    "remark": "充值办卡1",</code><code>    "acct_circle": "PG11111",</code><code>    "user_type": 92,</code><code>    "from_user_type": 90,</code><code>    "company_id": "PG11111",</code><code>    "profit_mode": 1,</code><code>    "type": 2,</code><code>    "parent_id": null,</code><code>    "oc_profit_id": "1784570096901248",</code><code>    "keep_account_from_user_id": null,</code><code>    "keep_account_from_bm_user_id": null,</code><code>    "keep_account_user_id": null,</code><code>    "keep_account_bm_user_id": null,</code><code>    "biz_company_id": "PG11111"</code><code>  },</code><code>  "source": {</code><code>    "version": "1.6.4.Final",</code><code>    "connector": "mysql",</code><code>    "name": "mysql_binlog_source",</code><code>    "ts_ms": 1686734882000,</code><code>    "snapshot": "false",</code><code>    "db": "cloud_test",</code><code>    "sequence": null,</code><code>    "table": "acct_profit",</code><code>    "server_id": 1,</code><code>    "gtid": null,</code><code>    "file": "mysql-bin.000514",</code><code>    "pos": 650576218,</code><code>    "row": 0,</code><code>    "thread": null,</code><code>    "query": null</code><code>  },</code><code>  "op": "u",</code><code>  "ts_ms": 1686734882689,</code><code>  "transaction": null</code><code>}</code></pre> </section> <section> </section> <section> </section> <section style="text-align: center;">     记录每一份热爱,让美好永远陪伴。 </section>

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