复制上一节中的项目MyBatis_Spring_DAO，命名为MyBatis_Spring_Mapper。删除dao包及包内所有文件、com.test/test/UserDaoTest.java，新建动态代理接口类mapper/UserMapper.java、测试类com.test/test/MapperTest.java，整理项目目录如下所示：

项目目录

修改Spring主配置文件applicationContext.xml。

<?xml version="1.0" encoding="UTF-8"?>
<beans 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns="http://www.springframework.org/schema/beans" 
    xmlns:aop="http://www.springframework.org/schema/aop" 
    xmlns:context="http://www.springframework.org/schema/context" 
    xmlns:tx="http://www.springframework.org/schema/tx" 
    xmlns:util="http://www.springframework.org/schema/util" 
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans.xsd 
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd 
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd 
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd 
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd ">
    
    <!-- 读取db.properties -->
    <context:property-placeholder location="db.properties"/>
    
    <!-- 配置c3p0连接池 -->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    
    <!-- 配置mybatis sqlSessionFactory -->
    <bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 配置数据源  -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 告诉spring mybatis的核心配置文件 -->
        <property name="configLocation" value="classpath:sqlMapConfig.xml"/>
    </bean>
    
    <!-- mapper动态代理开发 -->
    <bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
        <!-- 注入 sqlSessionFactory -->
        <property name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
        <!-- 配置接口 -->
        <property name="mapperInterface" value="com.test.mapper.UserMapper"/>
    </bean>
    
</beans>

给出其他新建文件的代码。
UserMapper.java：

package com.test.mapper;

import com.test.bean.User;

public interface UserMapper {
    //通过id查询一个用户
    public User selectUserById(Integer id);
}

MapperTest.java：

package com.test.test;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.test.bean.User;
import com.test.mapper.UserMapper;

public class MapperTest {
    
    @Test
    public void Test1() {
        
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserMapper mapper = (UserMapper) ac.getBean("userMapper");
        
        User user = mapper.selectUserById(1);
        System.out.println(user);
    }
}

注意修改UserMapper.xml和sqlMapConfig.xml的小细节。
UserMapper.xml中，

<mapper namespace="UserMapper">

改为

<mapper namespace="com.test.mapper.UserMapper">

。
sqlMapConfig.xml中，

<mappers>
        <mapper resource="com/test/mapper/UserMapper.xml"/> 
    </mappers>

改为

    <mappers>
         <package name="com.test.mapper"/>
    </mappers>

。

进行测试。

测试结果