java——枚举类

自定义枚举

package com.ruqi.test;
// 自定义枚举类
public class UseEnum{
    public static void main(String[] args) {
        System.out.println(Season.SPRING.getSeason());
    }
}

class Season {
//    1、定义属性且不可修改
    private final String season;
    private final String seasondesc;
//    2、定义私有构造器,为了可以定义不的枚举
    private Season(String season, String seasondesc){
        this.season = season;
        this.seasondesc = seasondesc;
    }

//    3、定义具体的枚举描述

    public static final Season SPRING = new Season("春天", "温暖");
    public static final Season SUMMER = new Season("夏天", "火热");

    public String getSeason() {
        return season;
    }

    public String getSeasondesc() {
        return seasondesc;
    }
}

enum枚举类，由自定义枚举演变过来

package com.ruqi.test;

enum SeasonEnum {

//    public static final Season SPRING = new Season("春天", "温暖");
//    public static final Season SUMMER = new Season("夏天", "火热");
//    重复的内容都去掉,并且用逗号分隔，最后分号
    SPRING("春天", "温暖"),
    SUMMER("夏天", "火热");

    //    1、定义属性且不可修改
    private final String season;
    private final String seasondesc;
    
    //   2、定义私有构造器,为了可以定义不同的枚举
     SeasonEnum(String season, String seasondesc){
        this.season = season;
        this.seasondesc = seasondesc;
    }


    public String getSeason() {
        return season;
    }

    public String getSeasondesc() {
        return seasondesc;
    }
}

3、常用api

package com.ruqi.test;

public class UseEnum{
    public static void main(String[] args) {
//        常用api
//        1、得到所有枚举的数组
        SeasonEnum[] list = SeasonEnum.values();
        for (SeasonEnum o : list) {
            System.out.println(o);
        }

//      2、toString，打印枚举的名字
        System.out.println(SeasonEnum.SPRING.toString());

//       3、valueOf,根据填充的名称，找到相应的枚举名称，没有则抛异常
        SeasonEnum S = SeasonEnum.valueOf("SPRING");
        System.out.println(S);
    }
}

4、枚举类实现接口

package com.ruqi.test;


interface Info{
    void show();
}

enum SeasonEnum implements Info{

    SPRING("春天", "温暖"){
        @Override
        public void show() {
            System.out.println("只会对春天重写");
        }
    },
    SUMMER("夏天", "火热"){
        @Override
        public void show() {
            System.out.println("只会对夏天重写");

        }
    };
    //    1、定义属性且不可修改
    private final String season;
    private final String seasondesc;

    //   2、定义私有构造器,为了可以定义不同的枚举
     SeasonEnum(String season, String seasondesc){
        this.season = season;
        this.seasondesc = seasondesc;
    }


    public String getSeason() {
        return season;
    }

    public String getSeasondesc() {
        return seasondesc;
    }

//    @Override
//    public void show() {
//        System.out.println("可以在整个类中重写，但所有的枚举都只能执行的这个重写方法");
//    }
}


=======================================

public class UseEnum{
    public static void main(String[] args) {
        SeasonEnum.SPRING.show();
    }
}