线程池创建线程并全部结束后执行主线程

import java.util.concurrent.*;

public class BankStatementQuery {
// 指定几个线程
    private  static final CountDownLatch countDownLatch = new CountDownLatch(3);
    public static void main(String[] args) {
        BlockingQueue<Runnable> bq = new ArrayBlockingQueue<Runnable>(10);
        // 创建线程池
        ScheduledExecutorService scheduledThreadPool = Executors.newScheduledThreadPool(5);
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(3, 5, 50, TimeUnit.MILLISECONDS, bq);

        threadPoolExecutor.execute(new Runnable() {
            @Override
            public void run() {

                try {
                    // 没有任何问题时，释放线程
                    countDownLatch.countDown();
                    System.out.printf("线程一");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        threadPoolExecutor.execute(new Runnable() {
            @Override
            public void run() {
                countDownLatch.countDown();
                System.out.printf("线程二");
            }
        });
        threadPoolExecutor.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    countDownLatch.countDown();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                System.out.printf("线程三");
            }
        });

        try {
            // 等待所有线程全部释放完成后，再去执行主线程
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.printf("执行完成");
        threadPoolExecutor.shutdown();
 
    }

}