Java 基础 enum枚举类 的创建/使用/接口继承 ,以及手动创建枚举类的对象为:public static final

笔记:

import java.lang.*;
/**一:枚举类 : enum Season implements info { s1(),s2(),s3(),s4()  };   //s1--s4 放在Season类的最上面!
 * 1.1.values() 返回一个包含整体的数组!
 * 2.valueof(String name),返回对应name的类, 必须是枚举类对象的名字,否则报错!
 * 3.实现接口,重写抽象方法 ,不同的枚举类可以有不同的方法
 */

 

枚举类代码:

interface info{
    void show();
}
enum Season implements info{
    Spring ("spring","春暖花开"){
        @Override
        public void show() {
            //super.show();
            System.out.println("春天在哪里!");
        }
    },
    Summer("spring","夏日炎炎"){
        public void show(){
            System.out.println("夏荷才露尖尖角!");
        }
    },
    Autumn("spring","秋高气爽"){
        @Override
        public void show() {
            // super.show();
            System.out.println("秋天像个傻子");
        }
    },
    Winter("spring","白雪皑皑"){
        @Override
        public void show() {
            super.show();
            System.out.println("冬天来了,年来了!");
        }
    };
    //1.提供类的属性,声明为private finall
    private final String seasonName;
    private final String seasonDesc;
    //2.声明为final属性,在构造器中初始化
    Season(String seasonName, String seasonDesc) {
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }
    //3.创建枚举类
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }
    //4.创建枚举类的对象为:public static final ,全局的常量

    @Override
    public String toString() {
        return "Season{" +
                "seasonName='" + seasonName + '\'' +
                ", seasonDesc='" + seasonDesc + '\'' +
                '}';
    }

    @Override
    public void show() {
        System.out.println("这是一个季节!");
    }
}
public class Test_enum {
    public static void main(String[] args) {
        //1.values()
        Season[] seasons= Season.values();
        for(int i=0;i<seasons.length;i++)
            System.out.println(seasons[i]);
        //2.valueof(String name),必须是枚举类对象的名字,否则报错!
        String str="Winter";
        Season s1=Season.valueOf(str);
        System.out.println("\n"+s1);
            //2.1枚举Thread 的几个方法
        System.out.println("\n"+"Thread枚举类的所有方法: ");
        Thread.State[] states = Thread.State.values();
        for(int i=0;i<states.length;i++)
            System.out.print(states[i]+"\t");
        System.out.println();
        //3.实现接口,重写抽象方法

    }
}

 

输出:

Season{seasonName='spring', seasonDesc='春暖花开'}
Season{seasonName='spring', seasonDesc='夏日炎炎'}
Season{seasonName='spring', seasonDesc='秋高气爽'}
Season{seasonName='spring', seasonDesc='白雪皑皑'}

Season{seasonName='spring', seasonDesc='白雪皑皑'}

Thread枚举类的所有方法: 
NEW    RUNNABLE    BLOCKED    WAITING    TIMED_WAITING    TERMINATED    

 

手动创建等价的枚举类:

  //  手动创建'枚举类',
class Season{
        //1.提供类的属性,声明为private finall
    private final String seasonName;
    private final String seasonDesc;
        //2.声明为final属性,在构造器中初始化
    public Season(String seasonName, String seasonDesc) {
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }
        //3.创建枚举类
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }
        //4.创建枚举类的对象为:public static final ,全局的常量
    public static final Season Spring = new Season("spring","春暖花开");
    public static final Season Summer = new Season("spring","夏日炎炎");
    public static final Season Autumn = new Season("spring","秋高气爽");
    public static final Season winter = new Season("spring","白雪皑皑");
    @Override
    public String toString() {
        return "Season{" +
                "seasonName='" + seasonName + '\'' +
                ", seasonDesc='" + seasonDesc + '\'' +
                '}';
    }
}