如何在Java中使用CountDownLatch实现等待

import java.util.concurrent.CountDownLatch;

public class Worker implements Runnable {
    private final CountDownLatch latch;

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

    public void run() {
        try {
            // 模拟工作耗时
            Thread.sleep(1000);
            System.out.println(Thread.currentThread().getName() + " 完成任务");
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        } finally {
            latch.countDown(); // 任务完成，计数减一
        }
    }
}

public class Main {
    public static void main(String[] args) throws InterruptedException {
        int workerCount = 3;
        CountDownLatch latch = new CountDownLatch(workerCount);

        for (int i = 0; i < workerCount; i++) {
            new Thread(new Worker(latch), "Worker-" + i).start();
        }

        System.out.println("主线程等待所有工作线程完成...");
        latch.await(); // 阻塞直到计数为0
        System.out.println("所有工作线程已完成，主线程继续执行。");
    }
}

主线程等待所有工作线程完成...
Worker-0 完成任务
Worker-1 完成任务
Worker-2 完成任务
所有工作线程已完成，主线程继续执行。

if (latch.await(5, TimeUnit.SECONDS)) {
    System.out.println("所有任务在5秒内完成");
} else {
    System.out.println("等待超时，部分任务可能未完成");
}