java（枚举）

1.自定义枚举类

public class Season {
    /**
     * 私有化属性并final修饰
     */
    private final String seasonName;
    private final String seasonDesc;

    /**
     * 私有化构造器
     * @param seasonName
     * @param seasonDesc
     */
    private Season(String seasonName, String seasonDesc) {
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }

    /**
     * 公共静态方法并final修饰
     */
    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","白雪皑皑");

    /**
     * 只有get方法，不能set(编译不通过)
     * @return
     */
    public String getSeasonName() {
        return seasonName;
    }

    public String getSeasonDesc() {
        return seasonDesc;
    }


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

public class SeasonTest {
    @Test
    public void test1() {
        Season spring = Season.SPRING;
        System.out.println(spring);

    }
}

 

2.使用enum关键字定义枚举类

/**
 * 使用enum关键字定义枚举类
 * 说明：定义的枚举类默认继承于java.lang.Enum类
 * 一，使用enum关键字定义的枚举类实现接口的情况
 * 情况1：实现接口，在enum类中实现抽象方法
 * 情况2：让枚举类的对象分别实现接口中的抽象方法
 */
interface info {
    void show();
}

public enum Season1 implements info{
    /**
     * 提供当前枚举类对象，多个对象以”,“隔开，末尾对象以”;"结束
     */
    SPRING("春天","春暖花开") {
        public void show() {
            System.out.println("春天在哪里");
        }
    },
    SUMMER("夏天","夏日炎炎") {
        public void show() {
            System.out.println("夏天适合游泳");
        }
    },
    AUTUMN("秋天","秋高气爽") {
        public void show() {
            System.out.println("秋风扫落叶");
        }
    },
    WINTER("冬天","白雪皑皑") {
        public void show() {
            System.out.println("大约在冬季");
        }
    };
    /**
     * 私有化属性并final修饰
     */
    private final String seasonName;
    private final String seasonDesc;

    /**
     * 私有化构造器
     * @param seasonName
     * @param seasonDesc
     */
    private Season1(String seasonName, String seasonDesc) {
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }


    /**
     * 只有get方法，不能set(编译不通过)
     * @return
     */
    public String getSeasonName() {
        return seasonName;
    }

    public String getSeasonDesc() {
        return seasonDesc;
    }


//    public void show() {
//        System.out.println("这是一个show方法");
//    }
}

 

public class Season1Test {
    @Test
    public void test1() {
        Season1 spring = Season1.SPRING;
        System.out.println(spring);
        //测试toString方法
        System.out.println(Season1.class.getSuperclass());

        //测试values方法
        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]);
        }

        System.out.println("--------");
        //values方法，返回枚举类对象名是objName的对象
        //如果没有objName的枚举类对象，则抛异常:IllegalArgumentException
       Season1 winter = Season1.valueOf("WINTER");
       // Season1 winter = Season1.valueOf("WINTER1");
        System.out.println(winter);
        winter.show();
    }

}

 

 

 

3.Eunm常用类的方法