mybatis: Using mapper interfaces with XML config f

2020-05-23 09:27发布

问题:

I like the XML notation for specifying global parameters such as connection strings. I also like Mapper annotations. When I try to combine the two, I get this exception.

Is there a way to combine the two? I would like to use an XML file for the global configurations, but have mybatis take Mapper interfaces into account.

The problem is that SqlSessionFactoryBuilder().build() takes either a Reader (which I want to use to pass the XML config), or a Configuration object (which I see has the addMappers() method that can help me) - but I don't understand how to combine the two.

回答1:

factory.getConfiguration().addMapper(...);



回答2:

When u create the mapper interface with the abstract methods having the exact method signature as the sql in the xml.

For eg. This was the namespace for the dao.xml which contained the actual query.

<mapper namespace=" com.mybatis.dao.EntityMapperInterface">
    <select id="selectEmployeeWithId" parameterType="Long"
        resultType="com.mybatis.domain.Employee">
        select id,name from employee where 1=1
        <if test="_parameter != null"> 
            AND id=#{id} 
        </if>
        order by id
    </select>

It will be mapped in the interface com.mybatis.dao.EntityMapperInterface

public interface EntityMapperInterface {
    public List<Employee> selectEmployeeWithId(Long id);

Mybatis-config file

<mappers>
    <mapper resource="com/mybatis/mappers/EntityMapper.xml" />
</mappers>

How do u call it from the Action class/Servlet? When u have the SqlSession initialized,

EntityMapperInterface emi = session.getMapper(EntityMapperInterface.class);
List eList = emi.selectEmployeeWithId(1);


回答3:

I had the same issue and was because the name space in mybatis mapper file and the package of the mapper interface were not matching.