整合思路
- SqlSessionFactory对象放入spring容器中作为单例实例存在
- mapper代理开发中,直接从spring容器中获得mapper的代理对象。
- 数据库的连接方式,数据库连接池,事物管理都交给spring容器来管理
- 传统的dao开发,从spring容器中获得sqlsession对象
整合步骤
导包
spring包(包括了SpringMvc)
mybatis包
数据库驱动和连接池包
mybatis核心和spring整合包
- 编写SqlMapConfig.xml配置文件
<?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>
<!-- 设置别名 -->
<typeAliases>
<!-- 2. 指定扫描包,会把包内所有的类都设置别名,别名的名称就是类名,大小写不敏感 -->
<package name="cn.itcast.mybatis.pojo" />
</typeAliases>
<!-- 引入mapper配置文件和接口的位置 -->
<mappers>
<package name="cn.itcast.mybatis.mapper"/>
</mappers>
</configuration>
- 数据库连接配置文件
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?characterEncoding=utf-8
jdbc.username=root
jdbc.password=root
- log4j文件
# 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配置文件
<?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">
<!-- 加载配置文件 -->
<context:property-placeholder location="classpath:db.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>
<!-- 配置SqlSessionFactory,产生SqlSessionFactory对象需要注入 dataSource数据源,和加载SqlMapConfig配置文件-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 配置数据源 -->
<property name="dataSource" ref="dataSource" />
<!-- 配置mybatis核心配置文件位置 -->
<property name="configLocation" value="classpath:SqlMapConfig.xml" />
</bean>
</beans>
- 编写UserMapper.xml配置文件
<?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="cn.itcast.mybatis.mapper.UserMapper">
<!-- 根据用户id查询 -->
<select id="queryUserById" parameterType="int" resultType="user">
select * from user where id = #{id}
</select>
<!-- 根据用户名模糊查询用户 -->
<select id="queryUserByUsername" parameterType="string"
resultType="user">
select * from user where username like '%${value}%'
</select>
<!-- 添加用户 -->
<insert id="saveUser" parameterType="user">
<selectKey keyProperty="id" keyColumn="id" order="AFTER"
resultType="int">
select last_insert_id()
</selectKey>
insert into user
(username,birthday,sex,address) values
(#{username},#{birthday},#{sex},#{address})
</insert>
</mapper>
- 编写UserMapper接口,与UserMapper.xml文件放在同一个目录下
public interface UserMapper {
/**
* 根据用户id查询
*
* @param id
* @return
*/
User queryUserById(int id);
/**
* 根据用户名模糊查询用户
*
* @param username
* @return
*/
List<User> queryUserByUsername(String username);
/**
* 添加用户
*
* @param user
*/
void saveUser(User user);
}
在spring配置文件中配置mapper代理
自动手动获得代理对象需要通过sqlSession来获得代理对象
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
交给spring容器管理后,就需要先给一个sqlSession对象,获得sqlSession对象,需要注入sqlSessionFactory。获得代理对象需要给一个Mapper对象的接口,所以将接口注入到MapperFactoryBean中
<!-- Mapper代理的方式开发方式一,配置Mapper代理对象,生成mapper实现类的工厂 -->
<bean id="userMapper" class="org.mybatis.spring.mapper.MapperFactoryBean">
<!-- 注入sqlSessionFactory -->
<property name="sqlSessionFactory" ref="sqlSessionFactory" />
<!-- 配置Mapper接口 -->
<property name="mapperInterface" value="cn.itcast.mybatis.mapper.UserMapper" />
</bean>
- 测试
package cn.itcast.mybatis.junit;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import cn.itcast.mybatis.mapper.UserMapper;
import cn.itcast.mybatis.pojo.User;
public class JunitTest {
@Test
public void testMapper() throws Exception {
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
//通过接口获得代理对象
UserMapper mapper = ac.getBean(UserMapper.class);
//通过id获得代理对象
//UserMapper mapper = (UserMapper) ac.getBean("userMapper");
User user = mapper.queryUserById(10);
System.out.println(user);
}
}
扫描开发(推荐)
- 修改applicationContext.xml配置文件
这里不需要注入sqlSessionFactory对象,因为一旦配置加载了sqlSessionFactory对象,就在spring的容器中,MapperScannerConfigurer会自动扫描获取 ,所以只需要指定基本包,就会自动扫描mapper配置文件。
<!-- Mapper动态代理开发—扫描-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 基本包 -->
<property name="basePackage" value="com.itheima.mybatis.mapper"/>
</bean>
- 测试
package cn.itcast.mybatis.junit;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import cn.itcast.mybatis.mapper.UserMapper;
import cn.itcast.mybatis.pojo.User;
public class JunitTest {
@Test
public void testMapper() throws Exception {
ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
//通过接口获得代理对象
UserMapper mapper = ac.getBean(UserMapper.class);
//通过id获得代理对象,由于通过自动扫描的方式获得,没有命名id,所以就不能通过这种方式获得mapper代理对象。
//UserMapper mapper = (UserMapper) ac.getBean("userMapper");
User user = mapper.queryUserById(10);
System.out.println(user);
}
}