在Java中如何使用CountDownLatch等待多线程完成任务_多线程同步实践经验

import java.util.concurrent.CountDownLatch;

public class TaskWorker implements Runnable {
    private final CountDownLatch latch;

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

    @Override
    public void run() {
        try {
            // 模拟任务执行
            System.out.println(Thread.currentThread().getName() + " 正在执行任务...");
            Thread.sleep(1000);
            System.out.println(Thread.currentThread().getName() + " 任务完成");
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        } finally {
            latch.countDown(); // 任务完成，计数减一
        }
    }

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

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

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

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