CountDownLatch和枚举配合使用

import java.util.concurrent.CountDownLatch;

public class CountDownLatchDemo {

    public static void main(String[] args) throws Exception {
        CountDownLatch countDownLatch = new CountDownLatch(6);
        for (int i = 1; i <= 6; i++) {
            new Thread(()->{
                System.out.println(Thread.currentThread().getName()+"\t 国，被灭");
                countDownLatch.countDown();
            },CountryEnum.forEach_CountryEnum(i).getRetMessage()).start();
        }
        countDownLatch.await();
        System.out.println(Thread.currentThread().getName()+"\t***秦帝国一统华夏");
    }

    public static void closeDoor() throws InterruptedException {
        CountDownLatch countDownLatch = new CountDownLatch(6);
        for (int i = 0; i <= 6; i++) {
            new Thread(() -> {
                System.out.println(Thread.currentThread().getName() + "\t上完自学，离开教室");
                countDownLatch.countDown();//减1
            }, String.valueOf(i)).start();
        }
        countDownLatch.await();
        System.out.println(Thread.currentThread().getName() + "\t****最后离开，关门");
    }
}

　　枚举：

import lombok.Getter;

public enum CountryEnum {
    ONE(1," 齐"),
    TWO(2,"楚"),
    THREE(3,"燕"),
    FOUR(4,"赵"),
    FIVE(5,"魏"),
    SIX(6,"韩");

    @Getter private Integer retCode;
    @Getter private String retMessage;

    CountryEnum(Integer retCode, String retMessage) {
        this.retCode = retCode;
        this.retMessage = retMessage;
    }

    public static CountryEnum forEach_CountryEnum(int index){
        CountryEnum[] myArray= CountryEnum.values();
        for(CountryEnum element: myArray){
            if(index==element.getRetCode()){
                return element;
            }
        }
        return null;
    }
}

　　

CountDownLatch 作用：让一些线程阻塞，直到另一个线程完成一系列操作后才被唤醒

CountDownLatch 主要有两个方法，当一个活多个线程调用await方法时，调用线程会被阻塞。其他线程调用coutDown方法会将技术器减1（调用countDown方法的线程不会阻塞），
当计数器的值变为0时，因为调用await方法被阻塞的线程会被唤醒，继续执行.