多线程 interrupt()方法

java interrupt()方法只是设置线程的中断标记，当对处于阻塞状态的线程调用interrupt方法时（处于阻塞状态的线程是调用sleep, wait, join 的线程)，会抛出InterruptException异常，而这个异常会清除中断标记。并且异常如果被捕获且没有重新抛出后续代码将继续执行。Thread.interrupt()方法不会中断一个正在运行的线程。这一方法实际上完成的是，在线程受到阻塞时抛出一个中断信号，这样线程就得以退出阻塞的状态。更确切的说，如果线程被Object.wait, Thread.join和Thread.sleep三种方法之一阻塞，那么，它将接收到一个中断异常（InterruptedException），从而提早地终结被阻塞状态。 

代码如下：

 

public class Main {
    @Test
    public void interruptedTest() {

        Runnable runnableError = () -> {
        //不会退出
            while (!Thread.interrupted()) {
                System.out.println(new Date());
                try {
                    TimeUnit.SECONDS.sleep(3);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //unreachable
            System.out.println("interrupted: " + Thread.interrupted());
        };
        //可以退出
        Runnable runnable = () -> {
            try {
                while (!Thread.interrupted()) {
                    System.out.println(new Date());
                    TimeUnit.SECONDS.sleep(3);
                }
                //unreachable
                System.out.println("interrupted: " + Thread.interrupted());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("reachable");
        };
        Thread thread = new Thread(runnable);

        thread.start();
        try {
            TimeUnit.SECONDS.sleep(2);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        thread.interrupt();
        try {
            thread.join();
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        assert (!thread.isInterrupted());
        System.out.println("end: " + new Date());
    }
}

特别需要注意的是：

Thread.Interrupted()除了会返回当前线程是否被中断之外，还会将线程状态恢复为未中断状态。而public boolean isInterrupted()不改变状态

代码如下：

    //清除状态
    public static boolean interrupted() {
        return currentThread().isInterrupted(true);
    }
    //保留状态
    public boolean isInterrupted() {
        return isInterrupted(false);
    }

　　

参考：

http://blog.csdn.net/u013238950/article/details/53893676

http://blog.csdn.net/wxwzy738/article/details/8516253