CountDownLatch 计数栓

1import java.util.concurrent.CountDownLatch;
2
3/**
4 * Created by zyBourn on 15/12/25.
5 */
6public class Entity {
7    public static void main(String[] args) {
8        //倒数计时 每执行一次countDown则减一次，总数减完后执行
9        CountDownLatch countDownLatch=new CountDownLatch(2);
10        new Racer(countDownLatch,"A").start();
11        new Racer(countDownLatch,"B").start();
12        new Racer(countDownLatch,"C").start();
13        new Racer(countDownLatch,"D").start();
14        for (int i=0;i<3;i++){
15            try{
16                Thread.sleep(1000);
17            }catch (InterruptedException e){
18                e.printStackTrace();
19            }
20            System.out.println(i);
21            countDownLatch.countDown();
22            if (i==2)
23                System.out.println("Start");
24        }
25    }
26}
27class Racer extends Thread{
28    private CountDownLatch countDownLatch;
29    public Racer(CountDownLatch countDownLatch,String name){
30        setName(name);
31        this.countDownLatch=countDownLatch;
32    }
33    public void run(){
34        try{
35            countDownLatch.await();
36            for(int i = 0;i<3;i++)
37                System.out.println(getName()+"=:"+i);
38        }catch (InterruptedException e){
39            e.printStackTrace();
40        }
41    }
42}