java学习笔记----枚举测试题

定义义一个交通灯枚举类，包含红灯、绿灯、黄灯，需要有获得下一个灯的方法，并实现红灯出现5秒之后变成绿灯，绿灯3秒之后变成黄灯，黄灯2秒之后变成红灯,如此循环

 public class Test5 {

      /**
       * @throws InterruptedException
       */
      public static void main(String[] args) throws InterruptedException {
           Deng[] deng = Deng. values();
            for( int i = 0;i < 3;i++){
               Deng d = deng[i];
                if(d == Deng. red){
                    System. out.println(d);
                    Thread. sleep(5000);
                    System. out.println(d.next());
               } else if(d == Deng. green){
                    Thread. sleep(3000);
                    System. out.println(d.next());
               } else if(d == Deng. yellow){
                    Thread. sleep(2000);
 //                 System.out.println(d.next());
                    i = -1;
               }
           }
      }
 }
 enum Deng{
      red("红灯"){
            public Deng next(){
                return green;
           }
      },green("绿灯"){
            public Deng next(){
                return yellow;
           }
      },yellow("黄灯"){
            public Deng next(){
                return red;
           }
      };
      public abstract Deng next();
      private String name;
      private Deng(String name){
            this. name = name;
      }
      @Override
      public String toString() {
            return name;
      }
 }