疑难杂症new Date() 造成的线程阻塞问题

Posted 2021-11-29 heben

代码如下

package com.learn.concurrent.probolem;

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

/**
 * @author wx
 * @Description
 * @date 2019/05/12 18:33
 */
public class DateProblem {
    public static void main(String[] args) {
        new DateProblem().execute();
    }

    public void execute() {
        CountDownLatch latch = new CountDownLatch(1);
        new Thread(new Worker(latch)).start();
        try {
            latch.await(); 
            System.out.println("work has been done");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    class Worker implements Runnable {

        private CountDownLatch latch;

        public Worker(CountDownLatch latch) {
            this.latch = latch;
        }

        @Override
        public void run() {
            System.out.println("point 1");
            System.out.println("point 2"+new Date());
            latch.countDown();
        }
    }
}

 

在上面红色代码出设置一个断点，发现只有"Point 1"这条消息输出了，"Point 2" 这条消息没有输出