Enum使用场景及技巧

Enum运用

这里只介绍enum的使用场景和技巧。
例子秦国灭六国
废话不多说上代码：

import lombok.Getter;
public enum  EnumDemo {
    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;

    EnumDemo(Integer retCode, String retMessage) {
        this.retCode = retCode;
        this.retMessage = retMessage;
    }
   	//遍历
    public static EnumDemo getCountryEnum(int index){
        EnumDemo[] values = EnumDemo.values();
        for (EnumDemo element:values) {
            if(index == element.getRetCode()){
                return element;
            }
        }
        return null;
    }
}


import java.util.concurrent.CountDownLatch;
public class CountDownLatchDemo {
    public static void main(String[] args) {

        CountDownLatch countDownLatch = new CountDownLatch(6);
        //模拟六国
        for (int i = 1; i <= 6; i++) {
            new Thread(()->{
                System.out.println(Thread.currentThread().getName()+" \t 国被灭");
                countDownLatch.countDown();//计数
            },EnumDemo.getCountryEnum(i).getRetMessage()).start();
        }
        try {
            countDownLatch.await();
            System.out.println(Thread.currentThread().getName()+"\t 秦国统一六国");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

运行结果：