多线程和并发库应用十五-CountDownLatch

本文主要是介绍多线程和并发库应用十五-CountDownLatch，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

CountDownLatch类位于java.util.concurrent包下，利用它可以实现类似计数器的功能,当计数为0后则执行

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();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();} 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();System.out.println("线程" + Thread.currentThread().getName() +"已发送命令，正在等待结果");cdAnswer.await();System.out.println("线程" + Thread.currentThread().getName() +"已收到所有响应结果");} catch (Exception e) {e.printStackTrace();}service.shutdown();}
}