interrupt和interrupted和isInterrupted的区别

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interrupt

Code Demo

 package org.fool.thread;

 public class InterruptTest1 {
     public static void main(String[] args) {
         Thread thread = new Thread(new Runnable() {
             @Override
             public void run() {
                 for (int i = 0; i < 100000; i++) {
                     System.out.println(Thread.currentThread().getName() + " i = " + i);
                 }
             }
         });

         thread.start();

         thread.interrupt();
     }
 } 

Note：

从运行结果来看，调用interrupt方法并没有停止线程

interrupted

Code Demo

 package org.fool.thread;

 public class InterruptTest2 {
     public static void main(String[] args) {
         Thread thread = new Thread(() -> {
             for (int i = 0; i < 10; i++) {
                 System.out.println(Thread.currentThread().getName() + " i = " + i);

                 if (i == 5) {
                     Thread.currentThread().interrupt();

                     System.out.println("interrupted 1: " + Thread.interrupted());

                     System.out.println("interrupted 2: " + Thread.interrupted());
                 }
             }
         });

         thread.start();

     }
 }

Console Output

Note：

控制台第一次打印的结果是true，第二次为false；Java Doc中给出的解释是：测试当前线程是否已经中断，线程的中断状态由该方法清除。即如果连续两次调用该方法，则第二次调用将返回false（在第一次调用已清除flag后以及第二次调用检查中断状态之前，当前线程再次中断的情况除外）

所以，interrupted()方法具有清除状态flag的功能

isInterrupted

Code Demo

 package org.fool.thread;

 public class InterruptTest3 {
     public static void main(String[] args) {
         Thread thread = new Thread(() -> {
             for (int i = 0; i < 10; i++) {
                 System.out.println(Thread.currentThread().getName() + " i = " + i);
             }
         });

         thread.start();

         // main thread interrupt
         Thread.currentThread().interrupt();

         System.out.println(thread.getName() + ":" + thread.isInterrupted());
         System.out.println(thread.getName() + ":" + thread.isInterrupted());
         System.out.println(Thread.currentThread().getName() + ":" + Thread.currentThread().isInterrupted());
         System.out.println(Thread.currentThread().getName() + ":" + Thread.currentThread().isInterrupted());

         // thread interrupt
         thread.interrupt();

         System.out.println(thread.getName() + ":" + thread.isInterrupted());
         System.out.println(thread.getName() + ":" + thread.isInterrupted());
     }
 }

Console Output

Summary

调用interrupt()方法仅仅是在当前线程中打了一个停止的标记，并不是真正的停止线程

interrupted()测试当前线程是否已经是中断状态，执行后具有清除中断状态flag的功能

isInterrupted()测试线程Thread对象是否已经是中断状态，但不清除中断状态flag