org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.Typ

- 日理万妓 2022-03-01 03:22 573阅读 0赞

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## 异常信息 ##

Caused by: org.apache.ibatis.builder.BuilderException: Error resolving class. Cause: org.apache.ibatis.type.TypeException: Could not resolve type alias 'categoryMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: categoryMap
        at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:103)
        at org.apache.ibatis.builder.xml.XMLStatementBuilder.parseStatementNode(XMLStatementBuilder.java:72)
        at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:135)
        at org.apache.ibatis.builder.xml.XMLMapperBuilder.buildStatementFromContext(XMLMapperBuilder.java:128)
        at org.apache.ibatis.builder.xml.XMLMapperBuilder.configurationElement(XMLMapperBuilder.java:118)
        ... 65 more
    Caused by: org.apache.ibatis.type.TypeException: Could not resolve type alias 'categoryMap'.  Cause: java.lang.ClassNotFoundException: Cannot find class: categoryMap
        at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:117)
        at org.apache.ibatis.builder.BaseBuilder.resolveAlias(BaseBuilder.java:130)
        at org.apache.ibatis.builder.BaseBuilder.resolveClass(BaseBuilder.java:101)
        ... 69 more
    Caused by: java.lang.ClassNotFoundException: Cannot find class: categoryMap
        at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:190)
        at org.apache.ibatis.io.ClassLoaderWrapper.classForName(ClassLoaderWrapper.java:89)
        at org.apache.ibatis.io.Resources.classForName(Resources.java:256)
        at org.apache.ibatis.type.TypeAliasRegistry.resolveAlias(TypeAliasRegistry.java:113)
        ... 71 more

--------------------

## 场景描述 ##

resultMap
    <resultMap id="categoryMap" type="category">
        <id property="id" column="a_id"/>
        <result property="name" column="a_name"/>
        <result property="parent_id" column="a_pid"/>
        <result property="species_num" column="a_count"/>
        <collection property="types" javaType="category">
            <id property="id" column="b_id"/>
            <result property="name" column="b_name"/>
            <result property="parent_id" column="b_pid"/>
            <result property="species_num" column="b_count"/>
        </collection>
    </resultMap>
    <select id="findOneCategory"  resultType="categoryMap">
        select a.id as a_id,a.name as a_name,a.parent_id as a_pid,a.species_num as a_count,b.id as b_id,b.name as b_name,b.parent_id as b_pid,b.species_num as b_count from category a inner join category b on a.id =b.parent_id
    </select>

--------------------

## 异常原因 ##

自定义的resultMap问题，应该把下面的resultType改为resultMap

--------------------

## 解决方案 ##

resultMap id="categoryMap" type="category">
        <id property="id" column="a_id"/>
        <result property="name" column="a_name"/>
        <result property="parent_id" column="a_pid"/>
        <result property="species_num" column="a_count"/>
        <collection property="types" javaType="category">
            <id property="id" column="b_id"/>
            <result property="name" column="b_name"/>
            <result property="parent_id" column="b_pid"/>
            <result property="species_num" column="b_count"/>
        </collection>
    </resultMap>
    <select id="findOneCategory"  resultMap="categoryMap">
        select a.id as a_id,a.name as a_name,a.parent_id as a_pid,a.species_num as a_count,b.id as b_id,b.name as b_name,b.parent_id as b_pid,b.species_num as b_count from category a inner join category b on a.id =b.parent_id
    </select>

--------------------

## 参考资料 ##

> 这里是引用

[Link 1]: https://www.jianshu.com/p/302c789b2799
[Link 2]: https://www.jianshu.com/p/052aaa7700e6
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