Java 使用 mybatis 的“MapperRegistry 不知道类型接口”异常

"Type interface is not known to the MapperRegistry" exception using mybatis

提问by ripper234

I'm setting up mybatis using annotations, and getting this helpful exception

我正在使用注释设置 mybatis，并得到这个有用的异常

org.apache.ibatis.binding.BindingException: Type interface org.foo.Bar is not known to the MapperRegistry

org.apache.ibatis.binding.BindingException：MapperRegistry 不知道类型接口 org.foo.Bar

Googling itdoesn't find anything, nor the user guide. What am I missing?

谷歌搜索没有找到任何东西，也没有用户指南。我错过了什么？

采纳答案by ripper234

OK, got it - this is happening because I was using a XML file for the configuration, and annotations for the mappers themselves - and mybatis doesn't find mapper annotations when using an XML config.

好的，明白了 - 发生这种情况是因为我使用 XML 文件进行配置，并为映射器本身使用注释 - 而 mybatis 在使用 XML 配置时找不到映射器注释。

See this followup question.

请参阅此后续问题。

回答by dolbysurnd

just for anyone who ended up here because they're new to mybatis http://www.mybatis.org/core/configuration.html
http://www.mybatis.org/mybatis-3/configuration.html

只适合那些因为对 mybatis 不熟悉而来到这里的人 http://www.mybatis.org/core/configuration.html
http://www.mybatis.org/mybatis-3/configuration.html

in the config file mappers section

在配置文件映射器部分

<mappers>
<mapper class="my.package.com.MyClass"/>
</mappers>

this will have you up and running with a config.xml and annotated interfaces

这将使您启动并运行 config.xml 和带注释的接口

回答by bobbyberg

It may be that your mapper.xml file is using the incorrect namespace (perhaps because of a copy paste error).

可能是您的 mapper.xml 文件使用了不正确的命名空间（可能是因为复制粘贴错误）。

For instance, let's say you have a Java interface called MyEntityMapper.javathat shouldbe linked to a mybatis mapper xml config called MyEntityMapper.xml:

例如，假设您有一个名为的 Java 接口MyEntityMapper.java，它应该链接到名为 的 mybatis 映射器 xml 配置MyEntityMapper.xml：

MyEntityMapper.java

MyEntityMapper.java

package my.mappers;

public interface MyEntityMapper {
    MyEntity getById(@Param("id") String id);
}

MyEntityMapper.xml

MyEntityMapper.xml

<?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="non.existent.package.NonExistentMapper">

    <resultMap id="MyEntityResultmap" type="MyEntity">
        <!-- some result map stuff here -->
    </resultMap>

    <select id="getByUuid" resultMap="MyEntityResultMap">
        <!-- some sql code here -->
    </select>
</mapper>

Notice that the namespaceattribute on the <mapper>element in MyEntityMapper.xmlis pointing to some non-existent mapper non.existent.package.NonExistentMapper, when really it should be pointing to my.mappers.MyEntityMapper.

请注意，in 元素namespace上的属性指向某个不存在的 mapper ，而实际上它应该指向。<mapper>MyEntityMapper.xmlnon.existent.package.NonExistentMappermy.mappers.MyEntityMapper

回答by Daniel de Zwaan

Type interface org.domain.classmapperis not known to the MapperRegistry

MapperRegistry不知道类型接口org.domain.classmapper

MyBatis throws this exception if the full package / class is not entered into the mapper xml namespace.

如果完整的包/类没有输入到映射器 xml 命名空间中，MyBatis 会抛出这个异常。

e.g. <mapper namespace="classmapper">causes exception, but

例如 <mapper namespace="classmapper">导致异常，但是

<mapper namespace="org.domain.classmapper">works

<mapper namespace="org.domain.classmapper">作品

回答by Green Lei

add Mapperclass to your SqlSessionFactory Configuration as this:

将Mapper类添加到您的 SqlSessionFactory 配置中，如下所示：

SqlSessionFactory factory = new SqlSessionFactoryBuilder()
            .build(reader);

//very import
factory.getConfiguration().addMapper(BarMapper.class);

SqlSession sqlSession = factory.openSession();

回答by inter18099

In your mapper.xml file mapper's namespace should be the path to the mapper interface.

在您的 mapper.xml 文件中，映射器的命名空间应该是映射器接口的路径。

for example:

例如：

<mapper namespace="com.mapper.LineMapper">
<select id="selectLine" resultType="com.jiaotong114.jiaotong.beans.Line">
select * from bus_line where id = #{id}
</select>
</mapper>

your mapper interface should be in com.mapper package and the name of it is LineMapper.

你的映射器接口应该在 com.mapper 包中，它的名字是 LineMapper。

回答by Maayan Hope

Happened to me when creating a shadowJar/bootJar for a spring boot project and using org.springframework.boot gradle plugin

在为 spring boot 项目创建 shadowJar/bootJar 并使用 org.springframework.boot gradle 插件时发生在我身上

When the jars are zipped inside the bootJar myBatis may fail to find the XML configuration files and will throw the described exception

当 jar 被压缩到 bootJar 中时，myBatis 可能无法找到 XML 配置文件并抛出所描述的异常

adding this block in the build.gradle file:

在 build.gradle 文件中添加这个块：

bootJar {
    requiresUnpack '**/MyProblematic.jar'
}

solved my problem

解决了我的问题