package com.java.concurrent;import java.util.concurrent.CountDownLatch;/** * CountDownLatch: 闭锁，在完成某些运算的时候，只有其它所有线程的运算全部完成后，当前运算才会执行 * @author fliay * */public class TestCountDownLatch {	public static void main(String[] args) {		final CountDownLatch latch = new CountDownLatch(10);		LactchDemo Ld = new LactchDemo(latch);		long start = System.currentTimeMillis();		for (int i = 0; i < 5; i++) {			new Thread(Ld).start();			new Thread(Ld).start();		}				try {			latch.await();//执行等待		} catch (InterruptedException e) {			// TODO Auto-generated catch block			e.printStackTrace();		}		long end = System.currentTimeMillis();		System.out.println("消耗时间为：" + (end - start));			}}class LactchDemo implements Runnable {	private CountDownLatch latch;	public LactchDemo(CountDownLatch latch) {		this.latch = latch;	}	public void run() {		synchronized (this) {			try {				for (int i = 0; i < 10; i++) {					if (i % 2 == 0) {						System.out.println(i);					}				}			} finally {				// 启动闭锁				latch.countDown();			}		}	}}