Java线程池ExecutorService和CountDownLatch的小例子

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * 模拟了100米赛跑，10名选手已经准备就绪，只等裁判一声令下。当所有人都到达终点时，比赛结束。
 * @author liuchao
 *
 */
public class Actor {

    public static void main(String[] args) throws InterruptedException {
        //10名运动员
        final CountDownLatch count = new CountDownLatch(10);

        //java的线程池
        final ExecutorService executorService = Executors.newFixedThreadPool(5);

        for(int index=1;index<=10;index++){
            final int number = index;
            executorService.submit(new Runnable() {
                public void run() {
                    try {
                        Thread.sleep((long) (Math.random()*10000));
                        System.out.println(number+": arrived");
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    } finally{
                        //运动员到达终点,count数减一
                        count.countDown();
                    }
                }
            });
        }
        System.out.println("Game Started");
        //等待count数变为0,否则会一直处于等待状态,游戏就没法结束了
        count.await();
        System.out.println("Game Over");
        //关掉线程池
        executorService.shutdown();
    }
}

运行结果

Game Started
5: arrived
1: arrived
2: arrived
3: arrived
8: arrived
4: arrived
6: arrived
9: arrived
7: arrived
10: arrived
Game Over