public enum CountryEnum {

    ONE(1,"春"),

    TWO(2,"夏"),

    THREE(3,"秋"),

    FOUR(4,"冬");

    private Integer retCode;

    private String reMessage;

    CountryEnum(int retCode, String reMessage) {

        this.retCode = retCode;

        this.reMessage = reMessage;

    }

    public String getReMessage() {

        return reMessage;

    }

    public Integer getRetCode() {

        return retCode;

    }

    public static CountryEnum forEachCountryEnum(int index){

        CountryEnum[] values = CountryEnum.values();

        for(CountryEnum value: values){

            if(index == value.getRetCode()){

                return value;

            }

        }

        System.out.println("not find " + index);

        return null;

    }

}

 public class TestDemo {

     public static void main(String[] args) throws InterruptedException {

         CountDownLatch countDownLatch = new CountDownLatch(4);

         for (int i = 1; i <= 4; i++) {

             new Thread(()->{

                 System.out.println(Thread.currentThread().getName()+"天来了......");

                 countDownLatch.countDown();//countDownLatch减一个

             }, CountryEnum.forEachCountryEnum(i).getReMessage()).start();

         }

         countDownLatch.await();//只有countDownLatch等于0才执行下一个线程(main线程)

         System.out.println("一年过去了...");

     }

 }