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整合思路
- SqlSessionFactory对象应该放到spring容器中作为单例存在
- 传统dao的开发方式中,应该从spring容器中获得sqlsession对象
- Mapper代理形式中,应该从spring容器中直接获得mapper的代理对象
- 数据库的连接以及数据库连接池事务管理都交给spring容器来完成
整合之前的工作
jar包
- spring的jar包
- Mybatis的jar包
- Spring+mybatis的整合包
- Mysql的数据库驱动jar包
- 数据库连接池的jar包
配置文件
- mybatis的配置文件sqlmapConfig.xml
- Spring的配置文件
- 数据库连接及连接池
- 事务管理(暂时可以不配置)
- sqlsessionFactory对象,配置到spring容器中
- mapeer代理对象或者是dao实现类配置到spring容器中
日志
# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
applicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<!-- 加载外部属性文件 -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 数据库连接池 -->
<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>
<!-- 创建工厂 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 配置数据源 -->
<property name="dataSource" ref="dataSource" />
<!-- 配置mybatis核心配置文件 -->
<property name="configLocation" value="classpath:SqlMapConfig.xml" />
</bean>
</beans>
数据源jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root
POJO
SqlMapConfig.xml
<?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="mapper/User.xml"/>
</mappers>
</configuration>
原始DAO开发模式
接口
package com.itheima.mapper;
import java.util.List;
import com.itheima.pojo.User;
public interface UserDao {
public User findUserById(Integer id);
}
实现类
package com.itheima.mapper;
import java.util.List;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import com.itheima.pojo.User;
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {
@Override
public User findUserById(Integer id) {
SqlSession session = super.getSqlSession();
return session.selectOne("test.selectUserById",id);
}
}
User.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="test">
<!-- 根据用户id查询 -->
<select id="selectUserById" parameterType="integer" resultType="com.itheima.pojo.User">
select * from user where id = #{id}
</select>
</mapper>
测试类
package com.itheima.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.itheima.mapper.UserDao;
import com.itheima.pojo.User;
public class UserDaoTest {
@Test
public void testFindUserById() {
//加载spring核心配置文件
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
User user = userDao.findUserById(1);
System.err.println(user);
}
}
使用mapper代理的方式
修改applicationContext.xml文件
方式1:
需要在SqlMapConfig.xml文件中,引入映射文件
<!-- Mapper代理的方式开发方式一,配置Mapper代理对象 -->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<!-- 注入要代理的Mapper接口类 -->
<property name="mapperInterface" value="com.itheima.mapper.UserDao" />
<!-- 注入工厂 -->
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
</bean>
方式2:
mapper接口类必须和mapper映射文件同包同名
不需要在SqlMapConfig.xml文件中,引入映射文件
<!-- Mapper代理的方式开发方式二,扫描包方式配置代理 -->
<!--
条件:mapper接口类必须和mapper映射文件同包同名
起名:mapper接口类名首字母小写
-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 配置Mapper接口 -->
<property name="basePackage" value="com.itheima.mapper" />
</bean>
applicationContext.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-4.0.xsd">
<!-- 加载外部属性文件 -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 数据库连接池 -->
<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>
<!-- 创建工厂 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 配置数据源 -->
<property name="dataSource" ref="dataSource" />
<!-- 配置mybatis核心配置文件 -->
<property name="configLocation" value="classpath:SqlMapConfig.xml" />
</bean>
<!-- Mapper代理的方式开发方式二,扫描包方式配置代理 -->
<!--
条件:mapper接口类必须和mapper映射文件同包同名
起名:mapper接口类名首字母小写
-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 配置Mapper接口 -->
<property name="basePackage" value="com.itheima.mapper" />
</bean>
</beans>
UserDao.java文件
package com.itheima.mapper;
import com.itheima.pojo.User;
public interface UserDao {
public User findUserById(Integer id);
}
UserDao.xml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">
<!-- namespace:命名空间,作用:1.用于隔离sql 2.使用动态代理开发DAO,namespace必须和Mapper接口类路径一致 -->
<mapper namespace="com.itheima.mapper.UserDao">
<select id="findUserById" parameterType="Integer"
resultType="com.itheima.pojo.User">
select * from user where id = #{id}
</select>
</mapper>
测试类
package com.itheima.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.itheima.mapper.UserDao;
import com.itheima.pojo.User;
public class UserDaoTest {
@Test
public void testFindUserById() {
//加载spring核心配置文件
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
UserDao userDao = (UserDao) applicationContext.getBean("userDao");
User user = userDao.findUserById(1);
System.err.println(user);
}
}