解决:Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for xxx

 

问题

mybatis启动时报以下错误信息

Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.xxx.xxx.server.mapper.AuthApplicationMapper.BaseResultMap
	at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:930)
	at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:887)
	at org.apache.ibatis.session.Configuration.addResultMap(Configuration.java:644)
	at org.apache.ibatis.builder.MapperBuilderAssistant.addResultMap(MapperBuilderAssistant.java:208)
	at org.apache.ibatis.builder.ResultMapResolver.resolve(ResultMapResolver.java:47)
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:289)
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElement(XMLMapperBuilder.java:253)
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.resultMapElements(XMLMapperBuilder.java:245)
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:118)
	... 71 more

 分析

从异常信息来看，意思 是Result Maps collection已经包含  AuthApplicationMapper.BaseResultMap了。就是在启动过程AuthApplicationMapper 存在两个 BaseResultMap

检查了xml代码AuthApplicationMapper.xml，发现只有一个BaseResultMap。按理说是不会报错呀

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xxx.xxx.server.mapper.AuthApplicationMapper">
  <resultMap id="BaseResultMap" type="com.xxx.smlds.model.AuthApplication">
    <[email protected]>
    <[email protected] auth_application-->
    <id column="id" jdbcType="VARCHAR" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="code" jdbcType="VARCHAR" property="code" />
    <result column="is_enable" jdbcType="NUMERIC" property="isEnable" />
    <result column="creator" jdbcType="VARCHAR" property="creator" />
    <result column="create_time" jdbcType="VARCHAR" property="createTime" />
    <result column="modifier" jdbcType="VARCHAR" property="modifier" />
    <result column="modify_time" jdbcType="VARCHAR" property="modifyTime" />
    <result column="icon_default" jdbcType="LONGVARCHAR" property="iconDefault" />
    <result column="icon_selected" jdbcType="LONGVARCHAR" property="iconSelected" />
  </resultMap>
  <sql id="Base_Column_List">
    <[email protected]>
    id, "name", code, is_enable, creator, create_time, modifier, modify_time, icon_default, 
    icon_selected
  </sql>
</mapper>

此时想到，编译运行时肯定肯定两个 AuthApplicationMapper.xml  文件。

经过排查是启动模块依赖的某个模块，也把xml文件外置编译了。如xml文件放在模块A 里， B,C 都依赖A且把xml外置，B又依赖C, 此时B启动时就会报以上错误。

解决

1. B 不依赖C,

2. C不外置xml

名词解释：xml外置

前提： B依赖A

B的pom.xml

   <!--B依赖A, 这里是B模块的pom.xml-->
    <build>
         <resource>
                <!--细粒度控制-->
                <directory>../A模块/src/main/resources</directory>
                <includes>
                    <include>mapper/**Mapper.xml</include>
                </includes>
            </resource>
       </build>

A/pom.xml 

 <!--这里是A 模块的pom.xml-->
 <resources>
            <!--由于顶层应用把mapper.xml外置了，这里不打包进去了，避免冲突。若单独运行则去掉-->
            <resource>
                <directory>src/main/resources</directory>
                <excludes>
                    <exclude>mapper/**Mapper.xml</exclude>
                </excludes>
            </resource>
        </resources>