从枚举值[duplicate]获取枚举名称

Question

public class Extensions {


    public enum RelationActiveEnum
    {
        Invited(0),
        Active(1),
        Suspended(2);

        private final int value;

        private RelationActiveEnum(final int value) {
            this.value = value;
        }
    }

        int dbValue = supp.ACTIVE;
        Extensions.RelationActiveEnum enumValue(dbValue);
        String stringName = enumValue.toString(); //Visible
        // OR
        int dbValuee = supp.ACTIVE;
        String stringValue = Enum.GetName(typeof(RelationActiveEnum), dbValue);

我应该工作，对吧？但它不是！！！！它告诉我dbValue可以转换为RelationActiveEnum...

Answer 1

由于您的“值”碰巧也与序数匹配，您可以只做以下操作：

public enum RelationActiveEnum {
    Invited,
    Active,
    Suspended;

    private final int value;

    private RelationActiveEnum() {
        this.value = ordinal();
    }
}

并从该值获取枚举：

int value = 1;
RelationActiveEnum enumInstance = RelationActiveEnum.values()[value];

我想静态方法将是一个很好的地方来放置它：

public enum RelationActiveEnum {
     public static RelationActiveEnum fromValue(int value) 
             throws IllegalArgumentException {
         try {
              return RelationActiveEnum.values()[value]
         } catch(ArrayIndexOutOfBoundsException e) {
              throw new IllegalArgumentException("Unknown enum value :"+ value);
         }
     }
}