- CountDownLatch:用于监听某些初始化操作,并且线程进行阻塞,等初始化执行完毕后,通知主线程继续工作执行
package com.example.core.juc;
import java.util.concurrent.CountDownLatch;
public class UseCountDownLatch {
public static void main(String[] args) {
CountDownLatch countDownLatch = new CountDownLatch(2);//需要两次唤醒
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println("进入t1线程");
try{
Thread.sleep(3000);//做一些初始化准备
}catch(InterruptedException e){
e.printStackTrace();
}
System.out.println("t1线程初始化完毕,通知t3线程继续操作");
countDownLatch.countDown();//通知t3
}
},"t1");
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println("进入t2线程");
try{
Thread.sleep(3000);//做一些初始化准备
}catch(InterruptedException e){
e.printStackTrace();
}
System.out.println("t2线程初始化完毕,通知t3线程继续操作");
countDownLatch.countDown();//通知t3
}
},"t2");
Thread t3 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println("进入t3线程,进入等待阶段");
try{
countDownLatch.await();//等待阶段,需要唤醒
}catch(InterruptedException e){
e.printStackTrace();
}
System.out.println("t3线程 进行后续的操作");
}
},"t3");
t1.start();
t2.start();
t3.start();
}
}
/*
进入t1线程
进入t2线程
进入t3线程,进入等待阶段
t1线程初始化完毕,通知t3线程继续操作
t2线程初始化完毕,通知t3线程继续操作
t3线程 进行后续的操作
*/