Mybatis条件if test如何使用枚举值

飞翔 2022-06-07 10:36:14

Mybatis条件if test使用枚举值

1.正确

package com.weather.weatherexpert.common.utils;
/**
 * <p>Title: </p>
 * <p>Description: </p>
 *
 * @Author
 * @CreateTime
 */
public enum City {
    XINZHOU(100002,"忻州"),
    DATONG(100003,"大同"),
    TAIYUAN(100001,"太原");
  
    private final Integer code;
    private final String name;
  
    City(Integer value, String desc) {
        this.code = value;
        this.name = desc;
    }
  
    public Integer getCode() {
        return code;
    }
  
    public String getName() {
        return name;
    }
}

xml：

<!--<if test="cityName == @com.weather.weatherexpert.common.utils.City.XINZHOU@getName"><!–wrong,java.lang.ClassNotFoundException: Unable to resolve class: com.weather.weatherexpert.common.utils.City.XINZHOU–>-->
<!--<if test="cityName == @com.weather.weatherexpert.common.utils.City@XINZHOU@getName"><!–wrong,[org.apache.ibatis.ognl.ParseException: Encountered " "@" "@ "" at line 1, column 65.–>-->
<if test="cityName == @com.weather.weatherexpert.common.utils.City@XINZHOU.getName"><!--right-->
    area_table
</if>
  
where 1=1
<if test="cityName == @com.weather.weatherexpert.common.utils.City@XINZHOU.getName"><!--right-->
    and city_name=#{cityName}
</if>

2.错误

package com.weather.weatherexpert.common.utils;
/**
 * <p>Title: </p>
 * <p>Description: </p>
 *
 * @Author
 * @CreateTime
 */
public class CityClass {
    public static enum CityEnum {
  
        XINZHOU(100002,"忻州"),
        DATONG(100003,"大同"),
        TAIYUAN(100001,"太原");
  
        private final Integer code;
        private final String name;
  
        CityEnum(Integer value, String desc) {
            this.code = value;
            this.name = desc;
        }
  
        public Integer getCode() {
            return code;
        }
  
        public String getName() {
            return name;
        }
    }
}

xml：

/*        Caused by: org.apache.ibatis.builder.BuilderException: Error evaluating expression
        'cityName == @com.weather.weatherexpert.common.utils.CityClass@CityEnum.XINZHOU.getName'. Cause: org.apache.ibatis.ognl.OgnlException:
        Could not get static field CityEnum from class com.weather.weatherexpert.common.utils.CityClass [java.lang.NoSuchFieldException: CityEnum]*/
        <if test="cityName == @com.weather.weatherexpert.common.utils.CityClass@CityEnum.XINZHOU.getName"><!--wrong-->
            area_table
        </if>

可见，直接定义的枚举类可以正常使用，在类中定义的枚举类这样使用会报错，可能方法还没有找到。

如下正确：

<if test="cityName == @com.a.b.c.CityClass$CityEnum@XINZHOU.getName"><!--right-->
 name = #{username}
</if>

Mybatis里使用枚举Enum判断

<if test="dtEnum == @com.xxx.xxx.TestTypeEnum@HOUR">
  DATE_FORMAT(TM,'%Y-%m-%d %H') as keyStr,
</if>

TestTypeEnum定义如下

HOUR("hour"),
DAY("day"),
MONTH("month"),
YEAR("year");