Java CountDownLatch示例代码

import java.util.Random;  
import java.util.concurrent.CountDownLatch;  
import java.util.concurrent.TimeUnit;  

public class Worker implements Runnable{  

    private CountDownLatch downLatch;  
    private String name;  

    public Worker(CountDownLatch downLatch,String name){  
        this.downLatch = downLatch;  
        this.name = name;  
    }  

    public void run() {  
        this.doWork();  
        try{  
            TimeUnit.SECONDS.sleep(new Random().nextInt(10));  
        }catch(InterruptedException ie){  
        }  
        System.out.println(this.name + "活干完了！");  
        this.downLatch.countDown();  

    }  

    private void doWork(){  
        System.out.println(this.name + "正在干活!");  
    }  

}  

import java.util.concurrent.CountDownLatch;  

public class Boss implements Runnable {  

    private CountDownLatch downLatch;  

    public Boss(CountDownLatch downLatch){  
        this.downLatch = downLatch;  
    }  

    public void run() {  
        System.out.println("老板正在等所有的工人干完活......");  
        try {  
            this.downLatch.await();  
        } catch (InterruptedException e) {  
        }  
        System.out.println("工人活都干完了，老板开始检查了！");  
    }  

}  

import java.util.concurrent.CountDownLatch;  
import java.util.concurrent.ExecutorService;  
import java.util.concurrent.Executors;  

public class CountDownLatchDemo {  

    public static void main(String[] args) {  
        ExecutorService executor = Executors.newCachedThreadPool();  

        CountDownLatch latch = new CountDownLatch(3);  

        Worker w1 = new Worker(latch,"张三");  
        Worker w2 = new Worker(latch,"李四");  
        Worker w3 = new Worker(latch,"王二");  

        Boss boss = new Boss(latch);  

        executor.execute(w3);  
        executor.execute(w2);  
        executor.execute(w1);  
        executor.execute(boss);  

        executor.shutdown();  
    }  

}  

王二正在干活!  
李四正在干活!  
老板正在等所有的工人干完活......  
张三正在干活!  
张三活干完了！  
王二活干完了！  
李四活干完了！  
工人活都干完了，老板开始检查了！