java-多线程分批处理，等待所有线程结束

public static void main(String[] args) {

    // 假设有5个上传任务
    int numberOfTasks = 5;
    // 初始化CountDownLatch
    CountDownLatch latch = new CountDownLatch(numberOfTasks);

    // 创建固定大小的线程池
    ExecutorService executor = Executors.newFixedThreadPool(numberOfTasks);

    for (int i = 0; i < numberOfTasks; i++) {
        // 为每个上传任务创建一个Runnable
        Runnable uploadTask = () -> {
            try {
                // 模拟上传任务
                System.out.println("Starting upload task " + Thread.currentThread().getName());
                Thread.sleep(((int) (Math.random() * 60) + 1) * 1000);
                System.out.println("Completed upload task " + Thread.currentThread().getName());
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                // 任务完成后，CountDownLatch的计数减1
                latch.countDown();
            }
        };
        // 执行任务
        executor.execute(uploadTask);
    }

    try {
        // 等待所有任务完成
        latch.await();
        System.out.println("All upload tasks are completed.");
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
        // 关闭线程池
        executor.shutdown();
    }
}