MyBatis 入门(三)--用接口方式访问数据库不配置mybatis-config.xml

      

public class TestUser {

    @Test
    public void TestSelectAll() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder()
                .build(inputStream);

        SqlSession session = sqlSessionFactory.openSession();

        if(!session.getConfiguration().getMapperRegistry().hasMapper(UserMapper.class))
            session.getConfiguration().addMapper(UserMapper.class);
        //这里获取session的配置文件，在MapperRegistry查看我们的接口方式是否已经注册
        //如果没有注册 则添加我们的接口

        try {

            UserMapper user = (UserMapper) session.getMapper(UserMapper.class);
            List<User> userlist = user.getAllUser();
            System.out.print(userlist);

        } finally {
            session.close();
        }

    }
}

最大的不同就是 mybatis-config.xml文件  
   

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
  PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  "">

<configuration>
    <properties resource="jdbc.properties" />
    <environments default="dev">
        <environment id="dev">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${driver}" />
                <property name="url" value="${url}" />
                <property name="username" value="${username}" />
                <property name="password" value="${password}" />
            </dataSource>
        </environment>
    </environments>
    <mappers>

    </mappers>
</configuration>

项目代码下载：