整合思路:
需要spring通过单例方式管理SqlSessionFactory。
spring和mybatis整合生成代理对象,使用SqlSessionFactory创建SqlSession。(spring和mybatis整合自动完成)
持久层的mapper都需要由spring进行管理。
1)加入jar包:
mybatis3.2.7的jar包;spring3.2.0的jar包;
mybatis和spring的整合包:mybatis-spring-1.2.2.jar
2)applicationContext.xml配置文件:
3)其他db.properties;log4j.properties和之前的一样;
一、使用原始dao接口开发(和spring整合后):
工程结构:
User.xml:
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd"> <mapper namespace="test">
<select id="findUserById" parameterType="int" resultType="com.ssm.po.User">
SELECT * FROM USER WHERE id=#{value}
</select>
</mapper>
SqlMapConfig.xml配置(加入User.xml的映射):
<?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>
<package name="com.ssm.po"/>
</typeAliases> <!-- 加载 映射文件 -->
<mappers>
<mapper resource="sqlMap/User.xml"/>
</mappers>
</configuration>
UserDao接口:
package com.ssm.dao; import com.ssm.po.User; public interface UserDao {
//根据id查询用户信息
public User findUserById(int id) throws Exception;
}
UserDaoImpl实现类(继承SqlSessionDaoSupport):
dao接口实现类需要注入SqlSessoinFactory,通过spring进行注入。
package com.ssm.dao; import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import com.ssm.po.User; public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao { @Override
public User findUserById(int id) throws Exception {
//继承SqlSessionDaoSupport,通过this.getSqlSession()得到sqlSessoin
SqlSession sqlSession = this.getSqlSession();
User user = sqlSession.selectOne("test.findUserById", id);
return user;
}
}
applicationContext.xml配置:
配置sqlSessionFactory、数据源、等、声明式配置UserDao的bean:
<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" /> <!-- 数据源,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 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 加载mybatis的配置文件 -->
<property name="configLocation" value="mybatis/SqlMapConfig.xml"></property>
<!-- 数据源 -->
<property name="dataSource" ref="dataSource"></property>
</bean> <!-- 原始dao接口 -->
<bean id="userDao" class="com.ssm.dao.UserDaoImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
</beans>
测试程序:
package com.ssm.dao; import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.ssm.po.User; public class UserDaoImplTest {
private ApplicationContext applicationContext; //在setUp这个方法得到spring容器
@Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
} @Test
public void testFindUserById() throws Exception {
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
User user = userDao.findUserById(1);
System.out.println(user);
}
}
二、使用mapper接口代理的方式开发:
UserMapper.xml:
<?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="com.ssm.mapper.UserMapper">
<select id="findUserById" parameterType="int" resultType="user">
SELECT * FROM USER WHERE id=#{value}
</select>
</mapper>
UserMapper接口:和UserMapper.xml位于同目录下
package com.ssm.mapper; import com.ssm.po.User; public interface UserMapper {
//根据id查询用户信息
public User findUserById(int id) throws Exception;
}
在SqlMapConfig.xml中加载UserMapper.xml映射文件:
<?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>
<package name="com.ssm.po"/>
</typeAliases> <!-- 加载 映射文件 -->
<mappers>
<package name="com.ssm.mapper"/>
</mappers>
</configuration>
在applicationContext.xml中通过MapperFactoryBean创建代理对象:
<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" /> <!-- 数据源,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 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 加载mybatis的配置文件 -->
<property name="configLocation" value="mybatis/SqlMapConfig.xml"></property>
<!-- 数据源 -->
<property name="dataSource" ref="dataSource"></property>
</bean> <!-- mapper配置 MapperFactoryBean:根据mapper接口生成代理对象-->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<!-- mapperInterface指定mapper接口 -->
<property name="mapperInterface" value="com.ssm.mapper.UserMapper"/>
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean> </beans>
测试代码:
package com.ssm.mapper; import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext; import com.ssm.po.User; public class UserMapperTest {
private ApplicationContext applicationContext; @Before
public void setUp() throws Exception {
applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
} @Test
public void testFindUserById() throws Exception {
UserMapper userMapper = (UserMapper) applicationContext.getBean("userMapper");
User user = userMapper.findUserById(1);
System.out.println(user);
} }
针对上面的applicationContext.xml中通过MapperFactoryBean创建代理对象,需要针对每个mapper进行配置,比较麻烦,
优化:通过MapperScannerConfigurer进行Mapper扫描:
于是applicationContext.xml配置修改为:
<!-- 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="com.ssm.mapper"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
而且和spring整合后,使用mapper扫描器,SqlMapConfig.xm这里不需要配置了
<!-- <package name="com.ssm.mapper"/> -->
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