public static void main(String[] args) throws InterruptedException {

        CountDownLatch latch =new CountDownLatch(10);

        for (int i = 0; i < 900; i++) {

            new Thread(new Runnable() {

                @Override

                public void run() {

                    System.out.println(Thread.currentThread().getName() );

                    try {

                        Thread.sleep(10000);

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    } finally {

                        latch.countDown();

                    }

                }

            }).start();

        }

        System.out.println("等待子线程运行结束");

        latch.await();

        System.out.println("子线程运行结束");

    }