11.线程通信CountDownLatch

package demo2;
import java.util.concurrent.CountDownLatch;
/**
 * Created by liudan on 2017/7/27.
 */
public class DemoCountDownLatch {
    public static void main(String[] args) {
        final CountDownLatch countDownLatch = new CountDownLatch(3);
        Thread t = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    System.err.print(">登录游戏：...	");
                    countDownLatch.await();
                    System.err.println("----------- 登录成功  SUCCESS-------------");
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"t");
        Thread t1 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(2000);
                    System.err.print(" 3 ");
                    countDownLatch.countDown();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"t1");
        Thread t2 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(3000);
                    System.err.print(" 2 ");
                    countDownLatch.countDown();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"t2");
        Thread t3 = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(4000);
                    System.err.println(" 1 ");
                    countDownLatch.countDown();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"t3");
        t.start();
        t1.start();
        t2.start();
        t3.start();
    }
}
输出：
>登录游戏：...	 3  2  1 
----------- 登录成功  SUCCESS-------------

null