不要使用静态内部类实现

好的，以下是不使用静态内部类的实现方式：

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

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

        ExecutorService executor = Executors.newFixedThreadPool(taskCount);

        for (int i = 0; i < taskCount; i++) {
            executor.submit(new Task(latch));
        }

        latch.await();
        System.out.println("All tasks have finished, now executing main task.");
        executor.shutdown();
    }
}

class Task implements Runnable {
    private CountDownLatch latch;

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

    @Override
    public void run() {
        try {
            System.out.println("Task started: " + Thread.currentThread().getName());
            Thread.sleep(1000);
            System.out.println("Task finished: " + Thread.currentThread().getName());
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            latch.countDown();
        }
    }
}

这个例子中，我们将 `Task` 类放在了独立的文件中，而不是作为静态内部类。其余部分的逻辑和之前的例子相同。通过传递 CountDownLatch 对象给每个任务，每个任务在完成时都会调用 `countDown()` 方法来减少计数器的值。主线程在调用 `await()` 方法等待计数器为 0 后才继续执行。