CountDownLatch 多线程使用示例

场景描述：

模拟10个线程，并发执行，最后汇总结果

代码：

1package com.jf.service.market.impl;
2
3import java.util.concurrent.CountDownLatch;
4import java.util.concurrent.ExecutorService;
5import java.util.concurrent.Executors;
6
7public class CountDownLatchTest {
8	
9   public static void main(String[] args) {
10	    int num = 10;
11	    long time = System.currentTimeMillis();
12	    ExecutorService cachedThreadPool = Executors.newCachedThreadPool();
13		final CountDownLatch latch = new CountDownLatch(num);
14		for (int i = 0; i < 10; i++) {
15			cachedThreadPool.execute(new Runnable() {
16				public void run() {
17					try {
18						Thread.sleep(1000);
19					} catch (InterruptedException e) {
20						e.printStackTrace();
21					}
22					System.out.println(" End=== Thread："+Thread.currentThread().getId()); 
23					latch.countDown();
24				}
25			});
26		}
27		try {
28			latch.await();
29		} catch (InterruptedException e) {
30			e.printStackTrace();
31		}
32		System.out.println("总共耗时:" + (System.currentTimeMillis()-time));
33		cachedThreadPool.shutdown();
34    }
35}

结果展示：

 End=== Thread：10
 End=== Thread：15
 End=== Thread：17
 End=== Thread：16
 End=== Thread：14
 End=== Thread：13
 End=== Thread：12
 End=== Thread：9
 End=== Thread：11
 End=== Thread：18
总共耗时:1008