<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"xmlns:context="http://www.springframework.org/schema/context"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd "><!-- 加载配置文件 --><context:property-placeholder location="classpath:db.properties"/><!-- 数据库连接池，使用dbcp --><bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"><property name="driverClassName" value="${jdbc.driver}"/><property name="url" value="${jdbc.url}"/><property name="username" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/><property name="maxActive" value="10"/><property name="maxIdle" value="5"/></bean><!-- SqlSessionFactory配置 --><!-- 让Spring管理SqlSessionFactory使用mybatis和spring整合包中的 --><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><!-- 数据库连接池 --><property name="dataSource" ref="dataSource" /><!-- 加载mybatis的全局配置文件 --><property name="configLocation" value="classpath:mybatis/SqlMapConfig.xml" /></bean></beans>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace命名空间，作用就是对sql进行分类化的管理，理解为sql隔离注意：使用mapper代理开发时，namespace有特殊作用  -->
<mapper namespace="test"><!--在映射文件中配置很多sql语句  --><!--需求：通过id查询用户表的记录  --><!--id：标识映射文件中的sql，称为statement的id。将sql语句封装在mapperStatement的对象中，所有id称为Statement的id；parameterType：指定输入参数的类型，这里指定int型；#{}:表示一个占位符；#{id}:其中id表示接收输入的参数，参数名称就是id，如果输入参数是简单类型，#{}中的参数名可以任意，可以是value或其它名称；resultType：指定输出结果所映射的Java对象类型，select指定resultType表示将单条记录映射成Java对象。--><select id="findUserById" parameterType="int" resultType="joanna.yan.po.User">select * from user where id=#{value}</select></mapper>

<?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><!-- 批量别名的定义：package:指定包名，mybatis会自动扫描包中的pojo类，自定义别名，别名就是类名（首字母大写或小写都可以） --><typeAliases><package name="joanna.yan.po"/></typeAliases><mappers><mapper resource="sqlmap/User.xml"/><!-- 批量加载映射配置文件，mybatis自动扫描包下的mapper接口进行加载；遵循一定的规范：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；以上规范的前提是：使用的是mapper代理方法;--><package name="joanna.yan.mapper"/></mappers></configuration>

public interface UserDao {//根据id查询用户信息public User findUserById(int id) throws Exception;
}

public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao{@Overridepublic User findUserById(int id) throws Exception {//继承SqlSessionDaoSupport，通过this.getSqlSession()得到sqlSessionSqlSession sqlSession=this.getSqlSession();User user=sqlSession.selectOne("test.findUserById", id);return user;}
}

 <!-- 方法一：原始dao接口  --><bean id="userDao" class="joanna.yan.dao.UserDaoImpl"><property name="sqlSessionFactory" ref="sqlSessionFactory" /></bean>

public class UserDaoImplTest {private ApplicationContext applicationContext;@Beforepublic void setUp(){applicationContext=new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");}@Testpublic void findUsetByIdTest() throws Exception{UserDao userDao=(UserDao) applicationContext.getBean("userDao");User user=userDao.findUserById(1);System.out.println(user);}
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--namespace命名空间，作用就是对sql进行分类化的管理，理解为sql隔离注意：使用mapper代理开发时，namespace有特殊作用，namespace等于mapper接口地址  -->
<mapper namespace="joanna.yan.mapper.UserMapper"><select id="findUserById" parameterType="int" resultType="user">select * from user where id=#{value}</select>
</mapper>

public interface UserMapper {public User findUserById(int id) throws Exception;
}

 <!-- 方法二：mapper配置MapperFactoryBean:根据mapper接口生成代理对象--><bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean"><property name="mapperInterface" value="joanna.yan.mapper.UserMapper" /><property name="sqlSessionFactory" ref="sqlSessionFactory" /></bean>

public class UserMapperTest {private ApplicationContext applicationContext;@Beforepublic void setUp(){applicationContext=new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");}@Testpublic void findUsetByIdTest() throws Exception{UserMapper userMapper=(UserMapper) applicationContext.getBean("userMapper");User user=userMapper.findUserById(1);System.out.println(user);}
}

 <!-- 方法三：mapper批量扫描 从mapper包中扫描出mapper接口，自动创建代理对象并且在spring容器中注册遵循规范：将mapper.java和mapper.xml映射文件名称保持一致，且在一个目录中。自动扫描出来的mapper的bean的id为mapper类名（首字母小写）--><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><!-- 指定扫描的包名如果扫描多个包，每个包中间使用半角逗号分隔--><property name="basePackage" value="joanna.yan.mapper"/><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/></bean>

@Testpublic void findUsetByIdTest() throws Exception{UserMapper userMapper=(UserMapper) applicationContext.getBean("userMapper");User user=userMapper.findUserById(1);System.out.println(user);}