技術標籤：mybatismybatisjavassm

1、錯誤的一些資訊：

Caused by: org.springframework.core.NestedIOException: Failed to parse mapping resource: 'file [D:\eclipse\eclipse_new_new\maven\ssm-crud3\target\classes\mapper\EmployeeMapper.xml]'; nested exception is org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML.
 
 The XML location is 'file [D:\eclipse\eclipse_new_new\maven\ssm-crud3\target\classes\mapper\EmployeeMapper.xml]'. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.feng.crud.dao.EmployeeMapper.mapper_resultMap[WithDeptResultMap]_association[department]
 

	at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:613)
	at org.mybatis.spring.SqlSessionFactoryBean.afterPropertiesSet(SqlSessionFactoryBean.java:491)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.
 
java:1855)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1792)
	... 41 more
Caused by: org.apache.ibatis.builder.BuilderException: Error parsing Mapper XML. The XML location is 'file [D:\eclipse\eclipse_new_new\maven\ssm-crud3\target\classes\mapper\EmployeeMapper.xml]'. Cause: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.feng.crud.dao.EmployeeMapper.mapper_resultMap[WithDeptResultMap]_association[department]
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:122)
	at org.apache.ibatis.builder.xml.XMLMapperBuilder.parse(XMLMapperBuilder.java:94)
	at org.mybatis.spring.SqlSessionFactoryBean.buildSqlSessionFactory(SqlSessionFactoryBean.java:611)
	... 44 more
Caused by: java.lang.IllegalArgumentException: Result Maps collection already contains value for com.feng.crud.dao.EmployeeMapper.mapper_resultMap[WithDeptResultMap]_association[department]
	at org.apache.ibatis.session.Configuration$StrictMap.put(Configuration.java:947)

2、原因：

根據以上報錯資訊錯誤原因是：
在這個檔案中EmployeeMapper.xml
裡面有很多相同的id值為WithDeptResult的相同的語句

下面的是個列子，反正就是類似的。

 <resultMap type="com.feng.crud.bean.Employee" id="WithDeptResultMap">
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="gender" jdbcType="CHAR" property="gender" />
    <result column="email" jdbcType="VARCHAR" property="email" />
    <result column="d_id" jdbcType="INTEGER" property="dId" />
    <association property="department" javaType="com.feng.crud.bean.Department">
    	<id column="id" property="id"/>
    	<result column="name" property="name"/>
    </association>
  </resultMap>
  
   <resultMap type="com.feng.crud.bean.Employee" id="WithDeptResultMap">
    <id column="id" jdbcType="INTEGER" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="gender" jdbcType="CHAR" property="gender" />
    <result column="email" jdbcType="VARCHAR" property="email" />
    <result column="d_id" jdbcType="INTEGER" property="dId" />
    <association property="department" javaType="com.feng.crud.bean.Department">
    	<id column="id" property="id"/>
    	<result column="name" property="name"/>
    </association>
  </resultMap>

3、解決辦法，根據報錯資訊，把對應的id值複製好，到對應的EmployeeMapper.xml檔案中Ctrl+F 查詢剛剛複製的id的值然後把那個語句塊刪除掉，或者註釋掉

4、產生那個錯誤的原因之一：
我這個是ssm（springmvc+spring+mybatis）框架的簡單crud（增刪改查），我使用的是mybatis的逆向工程（mybatis generator），在工程的mbg.xml檔案寫好之後並且寫好了那個對應的測試檔案，我重複執行了幾次這個檔案的測試檔案，就導致產生了多個相同的id值的相同語句在相同的*Mapper.xml檔案中（測試執行下一次之前沒有刪除之前的）。

5、發現這個錯誤參考了這個博主