1.列舉類的理解:類的物件只有有限個，確定的
2.當需要定義一組常量時，強烈建議使用列舉類
3.如果列舉類中只有一個物件，則可以作為單例模式的實現方式

package com.klvchen.java;

public class SeasonTest1 {
    public static void main(String[] args){
        Season1 summer = Season1.SUMMER;
        System.out.println(summer);

        System.out.println(summer.toString());

        System.out.println(Season1.
 
class.getSuperclass());

        System.out.println("********************");

        Season1[] values = Season1.values();
        for (int i = 0; i < values.length; i++){
            System.out.println(values[i]);
            values[i].show();
        }
        System.out.println("********************");
        Thread.State[] values1 
 
= Thread.State.values();
        for (int i = 0; i < values1.length; i++){
            System.out.println(values1[i]);
        }

        System.out.println("********************");
        Season1 winter = Season1.valueOf("WINTER");
        System.out.println(winter);
        winter.show();

    }
}

 
interface Info{
    void show();
}

//使用 enum 關鍵字列舉類
enum Season1 implements Info{
    //1.提供當前列舉類的物件，多個物件之間用","隔開，末尾物件";"結束
    SPRING("春天","春暖花開"){
        @Override
        public void show(){
            System.out.println("春天在哪裡?");
        }
    },
    SUMMER("夏天","夏日炎炎"){
        @Override
        public void show(){
            System.out.println("寧夏");
        }
    },
    AUTUMN("秋天","秋高氣爽"){
        @Override
        public void show(){
            System.out.println("秋天不回來");
        }
    },
    WINTER("冬天","冰天雪地"){
        @Override
        public void show(){
            System.out.println("大約在冬季");
        }
    };

    //2.宣告 Season 物件的屬性: private final 修飾
    private final String seasonName;
    private final String seasonDesc;

    //3.私有化類的構造器,並給物件屬性賦值
    private Season1(String seasonName,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }

    public String getSeasonName(){
        return seasonName;
    }

    public String getSeasonDesc(){
        return seasonDesc;
    }

    @Override
    public  void show(){
        System.out.println("這是一個季節");
    }
}