采用线程池实现多线程一：没有返回值

一：MyThread1 类

public class MyThread1 implements Runnable {
private CountDownLatch countDownLatch;
public MyThread1(CountDownLatch countDownLatch){
this.countDownLatch = countDownLatch;
}

@Override
public void run() {

Random random = new Random();

int randInt = random.nextInt();

System.out.println(randInt);

//递减锁存器的计数，如果计数到达零，则释放所有等待的线程
countDownLatch.countDown();
}

}

二：测试类
public class MyThread1Test {

public static void main(String[] args) throws InterruptedException {
CountDownLatch countDownLatch = new CountDownLatch(5);

//创建一个可重用固定线程数的线程池，以共享的无界队列方式来运行这些线程，在需要时使用提供的 ThreadFactory 创建新线程。
ExecutorService executorService = Executors.newFixedThreadPool(5);

for (int i = 0; i < 5; i++) {

//提交要执行的 Runnable 任务，并返回一个表示任务完成的 Future，可以提取或轮询此任务
executorService.submit(new MyThread1(countDownLatch));

}

//使当前线程在锁存器倒计数至零之前一直等待，除非线程被中断。
countDownLatch.await();//wait for all to finish

executorService.shutdown();

System.out.println("end ---------------- ");

}
}