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Java枚举类

作者:互联网

  1. 枚举类的说明:
  1. 如何自定义枚举类?步骤:
    //自定义枚举类
    class Season{
    //1.声明Season对象的属性:private final修饰
    private final String seasonName;
    private final String seasonDesc;

    //2.私化类的构造器,并给对象属性赋值
    private Season(String seasonName,String seasonDesc){
    this.seasonName = seasonName;
    this.seasonDesc = seasonDesc;
    }

    //3.提供当前枚举类的多个对象:public static final的
    public static final Season SPRING = new Season("春天","春暖花开");
    public static final Season SUMMER = new Season("夏天","夏日炎炎");
    public static final Season AUTUMN = new Season("秋天","秋高气爽");
    public static final Season WINTER = new Season("冬天","冰天雪地");

    //4.其他诉求1:获取枚举类对象的属性
    public String getSeasonName() {
    return seasonName;
    }

    public String getSeasonDesc() {
    return seasonDesc;
    }
    //4.其他诉求1:提供toString()
    @Override
    public String toString() {
    return "Season{" +
    "seasonName='" + seasonName + ''' +
    ", seasonDesc='" + seasonDesc + ''' +
    '}';
    }
    }

  2. jdk 5.0 新增使用enum定义枚举类。步骤:
    //使用enum关键字枚举类
    enum Season1 {
    //1.提供当前枚举类的对象,多个对象之间用","隔开,末尾对象";"结束
    SPRING("春天","春暖花开"),
    SUMMER("夏天","夏日炎炎"),
    AUTUMN("秋天","秋高气爽"),
    WINTER("冬天","冰天雪地");

    //2.声明Season对象的属性:private final修饰
    private final String seasonName;
    private final String seasonDesc;

    //2.私化类的构造器,并给对象属性赋值

    private Season1(String seasonName,String seasonDesc){
    this.seasonName = seasonName;
    this.seasonDesc = seasonDesc;
    }

    //4.其他诉求1:获取枚举类对象的属性
    public String getSeasonName() {
    return seasonName;
    }

    public String getSeasonDesc() {
    return seasonDesc;
    }

}

  1. 使用enum定义枚举类之后,枚举类常用方法:(继承于java.lang.Enum类)
    Season1 summer = Season1.SUMMER;
    //toString():返回枚举类对象的名称
    System.out.println(summer.toString());

// System.out.println(Season1.class.getSuperclass());
System.out.println("");
//values():返回所的枚举类对象构成的数组
Season1[] values = Season1.values();
for(int i = 0;i < values.length;i++){
System.out.println(values[i]);
}
System.out.println("
");
Thread.State[] values1 = Thread.State.values();
for (int i = 0; i < values1.length; i++) {
System.out.println(values1[i]);
}

    //valueOf(String objName):返回枚举类中对象名是objName的对象。
    Season1 winter = Season1.valueOf("WINTER");
    //如果没objName的枚举类对象,则抛异常:IllegalArgumentException

// Season1 winter = Season1.valueOf("WINTER1");
System.out.println(winter);

  1. 使用enum定义枚举类之后,如何让枚举类对象分别实现接口:
    interface Info{
    void show();
    }

//使用enum关键字枚举类
enum Season1 implements Info{
//1.提供当前枚举类的对象,多个对象之间用","隔开,末尾对象";"结束
SPRING("春天","春暖花开"){
@Override
public void show() {
System.out.println("春天在哪里?");
}
},
SUMMER("夏天","夏日炎炎"){
@Override
public void show() {
System.out.println("宁夏");
}
},
AUTUMN("秋天","秋高气爽"){
@Override
public void show() {
System.out.println("秋天不回来");
}
},
WINTER("冬天","冰天雪地"){
@Override
public void show() {
System.out.println("大约在冬季");
}
};
}

标签:Java,String,Season,枚举,seasonName,seasonDesc,public
来源: https://www.cnblogs.com/lihuafeng/p/15559099.html