How to solve Mybatis java.lang.IllegalArgumentException: Result Maps collection already contains value for X
- 2020-05-26 08:32:01
- OfStack
I need to integrate the framework spring, struts2 and mybatis3 for the project these two days. However, this error always occurs during the startup, which has puzzled me for a long time. The answers I found on the Internet are not what I wanted.
user - mapper. xml is as follows:
<?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.bmdc.dj.user.dao.UserDao">
<resultMap type="user" id="userResult">
<id property="user_id" column="USER_ID"/>
<result property="login_name" column="LOGIN_NAME"/>
<result property="real_name" column="REAL_NAME"/>
<result property="password" column="PASSWORD"/>
</resultMap>
<insert id="add" parameterType="user">
insert into users (user_id, login_name, real_name, password)
values(#{user_id}, #{login_name}, #{real_name}, #{password})
</insert>
</mapper>
Where namespace is the interface path.
Mybatis. xml as follows:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- The alias -->
<typeAliases>
<typeAlias type="com.bmdc.dj.user.domain.User" alias="user"/>
</typeAliases>
<mappers>
<mapper resource="com/bmdc/dj/user/dao/user-mapper.xml" />
</mappers>
</configuration>
The other configuration files are correct, so I won't write them. This will cause the error Java.lang.IllegalArgumentException: Result Maps collection already contains value for XXX.
The solution: delete Mybatis.xml < mappers > Tag all content. Because if the user-mapper.xml interface is in the same path as namespace, there is no need to reconfigure it in mybaits.xml.
The revised Mybatis.xml is as follows:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- The alias -->
<typeAliases>
<typeAlias type="com.bmdc.dj.user.domain.User" alias="user"/>
</typeAliases>
</configuration>