14.枚举类、注解

package com.atguigu.java;
/*
一：枚举类的使用
    1.枚举类的理解：类的对象是有限个、确定个的，称此类为枚举类
    2.当需要定义一组常量时，强烈推荐使用枚举类
    3.如果枚举类中只有一个对象，则可以作为单例模式的一种实现方式

二、如何定义枚举类
方式一： jdk5.0之前，自定义枚举类
方式二：jdk5.0，可以使用enum关键字定义枚举类

 */
public class SeasonTest {
    public static void main(String[] args) {
        Season spring = Season.SPRING;
        String s = spring.toString();
        System.out.println(s);
        //Season{seasonName=‘春天‘, seasonDesc=‘穿暖花开‘}
    }
}
//方式一：自定义枚举类
class Season{
    //1声明Season对象的属性,用private final修饰
    private final String seasonName;
    private final String seasonDesc;
   //2.私有化类的构造器,并给对象属性初始化
    private Season(String seasonName,String seasonDesc){
        this.seasonDesc = seasonDesc;
        this.seasonName = seasonName;
    }
    //3.提供当前枚举类的多个对象(外部可直接调用-静态方法)：public static final
    public static final Season SPRING = new Season("春天","穿暖花开");
    public static final Season SUMMER = new Season("夏天","夏日炎炎");
    public static final Season AUTUMN = new Season("秋天","果实累累");
    public static final Season WINTER = new Season("冬天","白雪皑皑");

    //4.其他诉求：获取枚举类对象的属性
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }
    @Override
    public String toString() {
        return "Season{" +
                "seasonName=‘" + seasonName + ‘\‘‘ +
                ", seasonDesc=‘" + seasonDesc + ‘\‘‘ +
                ‘}‘;
    }
}

package com.atguigu.java;
/*
二：使用enum关键字定义枚举类
   说明： 定义的枚举类默认继承与 java.lang.Enum 类


 */
public class SeasonTest1 {
    public static void main(String[] args) {
        Season autumn = Season.AUTUMN;
        System.out.println(autumn);
        //Season{seasonName=‘秋天‘, seasonDesc=‘果实累累‘}
    }

}
enum Season1 {
    //1.提供当前枚举类的对象，多个对象之间用","隔开，末尾的对象使用";"结束
    SPRING("春天", "穿暖花开"),
    SUMMER("夏天", "夏日炎炎"),
    AUTUMN("秋天", "果实累累"),
    WINTER ("冬天", "白雪皑皑");
    //2声明Season对象的属性,用private final修饰
    private final String seasonName;
    private final String seasonDesc;
    //3.私有化类的构造器,并给对象属性初始化
    private Season1(String seasonName, String seasonDesc) {
        this.seasonDesc = seasonDesc;
        this.seasonName = seasonName;
    }
    //4.其他诉求：获取枚举类对象的属性
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }
//    @Override
//    public String toString() {
//        return "Season1{" +
//                "seasonName=‘" + seasonName + ‘\‘‘ +
//                ", seasonDesc=‘" + seasonDesc + ‘\‘‘ +
//                ‘}‘;
//    }
}