public enum Week {
    MON{
        public String toLocaleString(){
            return "星期一";
        }
    },TUES{
        public String toLocaleString(){
            return "星期二";
        }
    },WEB{
        public String toLocaleString(){
            return "星期三";
        }

    },THUR{
        public String toLocaleString(){
            return "星期四";
        }

    },FRI{
        public String toLocaleString(){
            return "星期五";
        }

    },SAT{
        public String toLocaleString(){
            return "星期六";
        }

    },SUN{
        public String toLocaleString(){
            return "星期日";
        }

    };
    public abstract String toLocaleString();
}

枚舉的遍歷

復制代碼代碼如下:

public class EnumTest {
    public static void main(String[] args){
        for(Week w:Week.values()){
            System.out.println(w);
        }
    }
}

枚舉的常用方法

int compareTo方法

String name()返回枚舉實例的名稱

int ordinal() 返回枚舉值在枚舉中的索引

String toString()返回枚舉的實例名稱比name更常用

public static valueOf()

復制代碼代碼如下:

public class EnumTest {
    public static void main(String[] args){
        Week day =Week.FRI;
        System.out.println(day);//FRI
        System.out.println(day.name());//FRI
        System.out.println(day.ordinal());//4
        System.out.println(Week.valueOf("SUN").toLocaleString());//星期日
        System.out.println(Week.values().length);//7  獲取枚舉長度
    }
}

枚舉的構造函數(shù)

復制代碼代碼如下:

public enum Gender {
    MALE("男"),FEMALE("女");
    private String name;
    private Gender(String name){
        this.name =name;
    }
    public String getName(){
        return this.name;
    }
    public String toString(){
        String name = null;
        switch(this){
        case MALE:
            name="男";
            break;
        case FEMALE:
            name="女";
            break;
        }
        return name;
    }

}

枚舉的綜合應用示例：交通燈

復制代碼代碼如下:

public enum Lamp {
     /*每個枚舉元素各表示一個方向的控制燈*/    
     S2N("N2S","S2W",false),S2W("N2E","E2W",false),E2W("W2E","E2S",false),E2S("W2N","S2N",false),
     /*下面元素表示與上面的元素的相反方向的燈，它們的“相反方向燈”和“下一個燈”應忽略不計！*/
     N2S(null,null,false),N2E(null,null,false),W2E(null,null,false),W2N(null,null,false),
     /*由南向東和由西向北等右拐彎的燈不受紅綠燈的控制，所以，可以假想它們總是綠燈*/
     S2E(null,null,true),E2N(null,null,true),N2W(null,null,true),W2S(null,null,true);

     private Lamp(String opposite,String next,boolean lighted){
         this.opposite = opposite;
         this.next = next;
         this.lighted = lighted;
     }

 
     /*當前燈是否為綠*/    
     private boolean lighted;
     /*與當前燈同時為綠的對應方向*/    
     private String opposite;
     /*當前燈變紅時下一個變綠的燈*/    
     private String next;
     public boolean isLighted(){
         return lighted;
     }

     /**
      * 某個燈變綠時，它對應方向的燈也要變綠
      */    
     public void light(){
         this.lighted = true;
         if(opposite != null){
             Lamp.valueOf(opposite).light();
         }
         System.out.println(name() + " lamp is green，下面總共應該有6個方向能看到汽車穿過！");

     }

     /**
      * 某個燈變紅時，對應方向的燈也要變紅，并且下一個方向的燈要變綠
      * @return 下一個要變綠的燈
      */    
     public Lamp blackOut(){
         this.lighted = false;
         if(opposite != null){
             Lamp.valueOf(opposite).blackOut();
         }        

         Lamp nextLamp= null;
         if(next != null){
             nextLamp = Lamp.valueOf(next);
             System.out.println("綠燈從" + name() + "-------->切換為" + next);            
             nextLamp.light();
         }
         return nextLamp;
     }
 }