【工程截图（几个关键的标红框）】

【UserMapper.xml】

     
         
               SELECT * from USER WHERE id=#{id}      
     

【UserMapper.java】

package com.Higgin.Mybatis.mapper;import com.Higgin.Mybatis.po.User;public interface UserMapper {    //根据id查询用户信息    public User findUserById(int id) throws Exception;}

【sqlMapperConfig.xml】  

千万不要配置好了UserMapper.xml却忘记加载！

【UserMapperTest.java】

package com.Higgin.Mybatis.mapper.test;import static org.junit.Assert.*;import java.io.InputStream;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;import org.junit.Before;import org.junit.Test;import com.Higgin.Mybatis.mapper.UserMapper;import com.Higgin.Mybatis.po.User;public class UserMapperTest {        private SqlSessionFactory sqlSessionFactory ;        @Before    public void setUp() throws Exception {        //创建sqlSessionfactory        //MyBatis配置文件        String resource="SqlMapConfig.xml";        //得到配置文件流        InputStream inputStream=Resources.getResourceAsStream(resource);        //创建会话工厂，传入MyBatis的配置文件信息        sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);    }    @Test    public void testFindUserById() throws Exception {                SqlSession sqlSession =sqlSessionFactory.openSession();                //创建一个UserMapper对象,Mybatis自动生成mapper代理对象      UserMapper userMapper=sqlSession.getMapper(UserMapper.class);                //调用userMapper的方法        User user = userMapper.findUserById(5);                System.out.println(user.toString());    }}

【运行结果】