@IntDef替代枚举

• @IntDef/@StringDef本身是个Android中提供的一种注解.
• 添加依赖：compile 'com.android.support:support-annotations:22.0.0'

@IntDef({STRING,TEXT,BIGINT,BOOLEAN,DOUBLE,ATTACHMENT,
            ARRAY,HEARTRATE})
@Retention(RetentionPolicy.SOURCE)
public @interface DataType {     
        public static final int STRING = 0x00000001;
        public static final int TEXT = 0x00000002;
        public static final int BIGINT = 0x00000003;
        public static final int BOOLEAN = 0x00000004;
        public static final int DOUBLE = 0x00000005;
        public static final int ATTACHMENT = 0x00000006;
        public static final int ARRAY = 0x00000010;
        public static final int HEARTRATE = 0x00000021;
    }       

• 通过枚举，限制其他值不能传入，但是为什么要定义HiResearchDataType注解类？在哪里解析？限制变量作用，无实际逻辑，知识做值。https://www.kancloud.cn/zhangzihao/articles/325612