線程池創建線程並全部結束後執行主線程

package service.query;

import java.util.concurrent.*;

public class BankStatementQuery {
// 指定幾個線程
    private  static final CountDownLatch countDownLatch = new CountDownLatch(3);
    public static void main(String[] args) {
        BlockingQueue<Runnable> bq = new ArrayBlockingQueue<Runnable>(10);
        // 創建線程池
        ScheduledExecutorService scheduledThreadPool = Executors.newScheduledThreadPool(5);
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(3, 5, 50, TimeUnit.MILLISECONDS, bq);

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

                try {
                    // 沒有任何問題時，釋放線程
                    countDownLatch.countDown();
                    System.out.printf("線程一");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
        threadPoolExecutor.execute(new Runnable() {
            @Override
            public void run() {
                countDownLatch.countDown();
                System.out.printf("線程二");
            }
        });
        threadPoolExecutor.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    countDownLatch.countDown();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                System.out.printf("線程三");
            }
        });

        try {
            // 等待所有線程全部釋放完成後，再去執行主線程
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

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

}