package com.thread.test.Lock;

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

public class CountDownLatchDemo implements Runnable {

    static final CountDownLatch end = new CountDownLatch(10);//
 
 創建倒計時器，表示需要等待10個線程，等待在CountDownLatch上的線程才能繼續執行
    static final CountDownLatchDemo DEMO = new CountDownLatchDemo();

    public void run() {
        try {
            Thread.sleep(new Random().nextInt(10) * 1000);
            System.out.println(Thread.currentThread().getName() + "----check complete");
            end.countDown();
 
// 通知倒計時器一個線程完事兒,倒計時器減1
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        // 使用倒計時器來模仿火箭發射
        ExecutorService exec = Executors.newFixedThreadPool(10);// 創建10個線程的線程池
        for (int
 
 i = 0; i < 10; i++) {
            exec.submit(DEMO);
        }
        end.await();// 倒計時器需要等待10個線程的任務全部完成後，主線程才能繼續執行
        System.out.println("火箭發射");
        exec.shutdown();// 關閉線程池
    }

}

多線程控制工具類--倒計時器CountDownLatch的使用（模仿火箭發射）