java多线程同时执行和按顺序执行

package com.example.demo.util;

import java.util.concurrent.*;

public class ManyThread {
    static ExecutorService executorService = Executors.newCachedThreadPool();
    static ExecutorService executorService1 = Executors.newSingleThreadExecutor();

    public static void main(String[] args) {
//        sequentialExecution();
        countDownLatchTest();
    }

    public static void countDownLatchTest() {
//        CountDownLatch 指定线程执行完毕，在执行操作
        //同时执行线程
        CountDownLatch countDownLatch = new CountDownLatch(1);

        executorService.execute(() -> {
            try {
                countDownLatch.await();
                System.out.println("线程A执行，执行时间：" + System.currentTimeMillis());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }


        });

        executorService.execute(() -> {
            try {
                countDownLatch.aw