Mybatis与Spring的整合

1、导入jar包

2、创建SqlMapConfig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>

    <typeAliases>
        <typeAlias type="com.jack.po.User" alias="User"/>
    </typeAliases>
    <mappers>
        <mapper resource="com/jack/dao/user.xml" />
    </mappers>
</configuration>

3、创建User.xml映射文件

<?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">
<mapper namespace="test">
    <select id="findUser" parameterType="int" resultType="User">
        SELECT * FROM User WHERE id = #{value}
    </select>
</mapper>

4、创建Spring的配置文件

<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" />
    <!--配置数据源，使用dbcp-->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.name}" />
        <property name="password" value="${jdbc.pwd}" />
    </bean>
    <!--配置SqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean" >
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:SqlMapConfig.xml" />

    </bean>
    <!--配置接口得实现类-->
    <bean id="userImpl" class="com.jack.dao.impl.UserImple">
        <property name="sqlSessionFactory" ref="sqlSessionFactory" />
    </bean>
</beans>

5、接口文件

public interface UserDao {
    public User findUser(int id) throws Exception;
}

6、接口实现

public class UserImple extends SqlSessionDaoSupport implements UserDao {

	    public User findUser(int id) throws Exception {
	        SqlSession session = this.getSqlSession();
	        User user = session.selectOne("findUser",id);
	        return user;
	    }
	
	}

7、测试代码

public class Test {

    private ApplicationContext applicationContext;

    @Before
    public void setUp() throws Exception{
        applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

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

}

8、使用Mapper代理开发方式

1、通过MapperFactoryBean创建代理对象

（1）Mapper.xml和mapper接口文件保持不变
（2）Spring配置文件如下：

<!-- mapper配置 
MapperFactoryBean：根据mapper接口生成代理对象
mapperInterface指定mapper接口
-->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    <property name="mapperInterface" value="com.jack.mapper.Mapper"/>
</bean>

（3）测试代码：

  public void testFindUserById1() throws  Exception{
        Mapper mapper = (Mapper) applicationContext.getBean("userMapper");
        User user = mapper.findUser(1);
        System.out.println(user);
    }

（4）缺点：每一个mapper都要件bean配置，过于麻烦。

2、通过MapperScannerConfigurer进行mapper扫描（建议使用）

（1）Mapper.xml和mapper接口文件保持不变
（2）如果将mapper.xml和mapper接口的名称保持一致且放在一个目录 则不用在sqlMapConfig.xml中进行配置。
（3）Spring配置文件如下：

<!-- 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="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    <property name="basePackage" value="com.jack.mapper"/>
</bean>

（4）测试代码：

  public void testFindUserById2() throws  Exception{
        Mapper mapper = (Mapper) applicationContext.getBean("mapper");
        User user = mapper.findUser(1);
        System.out.println(user);
    }