java一个线程在另外3个线程执行完后执行，怎么写

[Oversdownload]

如题，求大神忙里抽闲给解疑下，谢谢。

[李德胜1995]

Thread的join(),java.util.concurrent包下的CountDownLatch和CyclicBarrier都可以做。。。。

[X元素]

利用CountDownLatch 可以解决。

[放开那禽兽冲我来]

thread.join()

[Jcon_]

package count_down_latch;

import java.util.Date;
import java.util.concurrent.CountDownLatch;

public class Test {

	public static void main(String[] args) throws InterruptedException {
		CountDownLatch latch = new CountDownLatch(3);
		Worker worker1 = new Worker("zhangsan", 5000, latch);
		Worker worker2 = new Worker("lisi", 8000, latch);
		Worker worker3 = new Worker("wangwu", 10000, latch);
		worker1.start();
		worker2.start();
		worker3.start();
		latch.await(); // 等待所有工人完成工作
		System.out.println("all work done at " + new Date());
		
	}
}

class Worker extends Thread{
	String workerName;
	int workerTime;
	CountDownLatch latch;
	
	public Worker(String workerName, int workerTime, CountDownLatch latch) {
		this.workerName = workerName;
		this.workerTime = workerTime;
		this.latch = latch;
	}
	
	@Override
	public void run() {
		System.out.println("worker " + workerName + " do work begin at " + new Date());
		doWork(); // 工作了
		System.out.println("woker " +workerName + " do work end at " + new Date());
		 latch.countDown();//工人完成工作，计数器减一  
	}
	
	private void doWork(){
		try {
			Thread.sleep(workerTime);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

[soton_dolphin]

用 cyclicBarrier