自定義列舉類：

/**
 * @Date: 2018/12/3 11:18
 * @Description: 自定義列舉類
 */
public class testEnum {

    public static void main(String args[]) {

        Season spring = Season.SPRING;
        System.out.println(spring);

    }
}

//自定義列舉類
class Season{

    //1.提供類的屬性，宣告為 private final
    private final String seasonName;
    private final String seasonDesc;

    //2.宣告為final的屬性，在構造器中初始化
    private Season(String seasonName ,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }

    //3.通過公共的方法來呼叫屬性
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }

    //4.建立列舉類的物件:將類的物件宣告 public static final
    private static final Season SPRING= new Season("spring","春暖花開");
    private static final Season SUMMER= new Season("summer","夏日炎炎");
    private static final Season AUTUMN= new Season("autumn","秋高氣爽");
    private static final Season WINTER= new Season("winter","白雪皚皚");


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

 若列舉只有一個物件，則可以作為是一種單例模式的實現方式。

使用enum  定義列舉類：

/**
 * @Date: 2018/12/3 11:18
 * @Description:
 *  列舉類
 *  1.如何自定義列舉類
 *  2.如何使用enum 關鍵字定義列舉類
 *     > 常用的方法
 *     > 如何讓列舉類實現介面
 *   values():將列舉類裡面的所有的物件以陣列的形式返回。
 *   valueof():傳入string型別的引數，返回string的物件（返回列舉類的物件）
 */
public class testEnum1 {

    public static void main(String args[]) {

        Season1 spring = Season1.SPRING;
        System.out.println(spring);

        spring.show();

        //1.values()
        Season1[] season1s = Season1.values();
        for (int i=0;i<season1s.length; i++){
            System.out.println(season1s[i]);
        }

        //2.valueof(String name):要求傳入的形參name是列舉類物件的名字。
        //否則，報  java.lang.IllegalArgumentException 異常
        String str = "SPRING";
        Season1 season1 = Season1.valueOf(str);
        System.out.println(season1);

        Thread.State[] values = Thread.State.values();
        for (int i =0 ; i< values.length ; i++){
            System.out.println(values[i]);
        }
    }
}

interface Info{
    void show();
}

//自定義列舉類
enum  Season1 implements Info{

    SPRING("spring","春暖花開"),
    SUMMER("summer","夏日炎炎"),
    AUTUMN("autumn","秋高氣爽"),
    WINTER("winter","白雪皚皚");


    //1.提供類的屬性，宣告為 private final
    private final String seasonName;
    private final String seasonDesc;

    //2.宣告為final的屬性，在構造器中初始化
    private Season1(String seasonName ,String seasonDesc){
        this.seasonName = seasonName;
        this.seasonDesc = seasonDesc;
    }

    //3.通過公共的方法來呼叫屬性
    public String getSeasonName() {
        return seasonName;
    }
    public String getSeasonDesc() {
        return seasonDesc;
    }

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

    public void show(){
        System.out.println("123456789");
    }
}
 

執行結果：