thread.interrupt()方法用来立刻终止当前线程。例如有一个请求时间很长，需要终止。

下面用网购超过3天未发货要求退货说明用法：

/**
 * interrupt模拟超期退货
 * 超过3天未发货，要求退货
 */
public class Demo implements Runnable{
    public static void main(String[] args) {
        System.out.println("双11到了，大家购物吧");
        for (int i = 0; i < 5; i++) {
            new Thread(new Demo()).start();
        }
        try {
            Thread.sleep(3000);  //
            System.out.println("过去3天了...");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        ThreadGroup threadGroup = Thread.currentThread().getThreadGroup(); // 当前threadGroup
        Thread[] threads = new Thread[Thread.activeCount()]; // 线程数组
        threadGroup.enumerate(threads); // 复制threadGroup中的线程到线程数组里面
        for (int i = 0; i < Thread.activeCount(); i++){
            threads[i].interrupt();
        }

    }

    @Override
    public void run() {
        try {
            System.out.println(Thread.currentThread().getName()+" 已下单");
            int n=(2+(int)(Math.random()*(6-2)))*1000; // 2-5秒
            Thread.sleep(n);
            System.out.println(Thread.currentThread().getName()+" 已发货");
        } catch (InterruptedException e) {
            System.out.println(Thread.currentThread().getName()+ " 3天还不发货，别发了，退货吧");
        }
    }
}