Enum学习使用

1.Enum枚举定义

/**
 * Query 规则 常量
 * @Author Scott
 * @Date 2019年02月14日
 */
public enum QueryRuleEnum {

    GT(">","gt","大于"),
    GE(">=","ge","大于等于"),
    LT("<","lt","小于"),
    LE("<=","le","小于等于"),
    EQ("=","eq","等于"),
    NE("!=","ne","不等于"),
    IN("IN","in","包含"),
    LIKE("LIKE","like","全模糊"),
    LEFT_LIKE("LEFT_LIKE","left_like","左模糊"),
    RIGHT_LIKE("RIGHT_LIKE","right_like","右模糊"),
    SQL_RULES("USE_SQL_RULES","ext","自定义SQL片段");

    private String value;
    
    private String condition; 

    private String msg;

    QueryRuleEnum(String value, String condition, String msg){
        this.value = value;
        this.condition = condition;
        this.msg = msg;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

      public String getCondition() {
        return condition;
    }

    public void setCondition(String condition) {
        this.condition = condition;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
       //通过value值获取枚举
    public static QueryRuleEnum getByValue(String value){
        if(oConvertUtils.isEmpty(value)) {
            return null;
        }
        for(QueryRuleEnum val :values()){
            if (val.getValue().equals(value) || val.getCondition().equals(value)){
                return val;
            }
        }
        return  null;
    }
}

2.枚举使用

String value ="gt";
QueryRuleEnum rule =null;

rule = QueryRuleEnum.getByValue(val);
//或rule = QueryRuleEnum.LIKE;
switch (rule) {
        case GT:
            //queryWrapper.gt(name, value);
            break;
                    }