Java5 多线程(六)--CountDownLatch 同步工具类

详细代码如下:

public class CountdownLatchTest {

public static void main(String[] args) {

ExecutorService service = Executors.newCachedThreadPool();

final CountDownLatch cdOrder = new CountDownLatch(1);

final CountDownLatch cdAnswer = new CountDownLatch(3);

for (int i = 0; i < 3; i++) {

Runnable runnable = new Runnable() {

public void run() {

try {

System.out.println("线程"

+ Thread.currentThread().getName() + "正准备接受命令");

cdOrder.await();//直到cdOrder的计数器归0,才能往下执行

//如果把这个程序比喻成一个3个运动员在比赛,还有一个裁判

//cdOrder的计数器归0,表明裁判名枪了,运动员可以跑了.

System.out.println("线程"

+ Thread.currentThread().getName() + "已接受命令");

Thread.sleep((long) (Math.random() * 10000));

System.out.println("线程"

+ Thread.currentThread().getName()

+ "回应命令处理结果");

cdAnswer.countDown();//每一个运动员到此计数器就减一,

} catch (Exception e) {

e.printStackTrace();

}

}

};

service.execute(runnable);

}

try {

Thread.sleep((long) (Math.random() * 10000));

System.out.println("线程" + Thread.currentThread().getName()

+ "即将发布命令");

cdOrder.countDown();//cdOrder的计数器减1,

System.out.println("线程" + Thread.currentThread().getName()

+ "已发送命令，正在等待结果");

cdAnswer.await();//cdAnswer直到计数器为0,也就是上面三个线程执行完毕,

//裁判就可以公布成绩了

System.out.println("线程" + Thread.currentThread().getName()

+ "已收到所有响应结果");

} catch (Exception e) {

e.printStackTrace();

}

service.shutdown();

}

}

执行结果如下:

转载请注明出处 :http://blog.csdn.net/johnny901114/article/details/8695726