1.mapper.xml

在config下新建sqlmap包，包中新建User.xml

User.xml

<mapper namespace="test">
    <select id="findeUserById" parameterType="int" resultType="com.chinglee.ssm.po.User">
        SELECT * FROM USER WHERE id=#{value}
    </select>
</mapper>

2. Sqlmapconfig中加载xml文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org/DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--加载映射文件-->
    <mappers>
        <mapper resource="sqlmap/User.xml"/>
        <!--批量加载mapper
           指定mapper接口的包名，mybatis自动扫描包下面所有mapper接口进行加载
           遵循一些规范：需要将mapper接口类名和mapper.xml映射文件名称保持一致，且在一个目录中
         前提：使用mapper代理的方法
        -->
        <!-- <package name="com.chinglee.mybatis.mapper"/>-->
    </mappers>

</configuration>

3.DAO接口

DAO接口

4.DAO接口实现类

• dao接口实现类需要注入SqlSessionFactory，通过spring进行注入。
  这里spring声明配置方式，配置dao的bean:
  在applicationContext.xml中配置

<!--原始dao接口-->
    <bean id="userDao" class="com.chinglee.ssm.dao.UserDaoImpl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

• 让UserDaoImpl实现类继承SqlSessionDaoSupport

package com.chinglee.ssm.dao;

import com.chinglee.ssm.po.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;

/**
 * Created by Administrator on 2017/11/2 0002.
 */
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {

    @Override
    public User findUserById(int id) throws Exception {
       //继承SqlSessionDaoSupport，通过this.getSqlSession()得到sqlSession
        SqlSession sqlSession=this.getSqlSession();
        User user=sqlSession.selectOne("test.findUserById",id);
        return user;
    }
}

5.测试

package com.chinglee.ssm.dao;

import com.chinglee.ssm.po.User;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Created by Administrator on 2017/11/2 0002.
 */
public class UserDaoImplTest {
    private ApplicationContext applicationContext;
    //在setUp方法得到spring容器
    @Before
    public void setUp() throws Exception {
       applicationContext=new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
    }

    @Test
    public void findUserById() throws Exception {
         UserDao userDao= (UserDao) applicationContext.getBean("userDao");
         User user=userDao.findUserById(1);
         System.out.println(user);
    }

}