一 环境搭建
1 maven jar包
<!--mysql驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.18</version>
</dependency>
<!--c3p0数据包-->
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
<!--servlet包-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<!--测试包-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<!--json包-->
<dependency>
<groupId>net.sf.json-lib</groupId>
<artifactId>json-lib</artifactId>
<version>2.4</version>
<classifier>jdk15</classifier>
</dependency>
<!--Spring 包-->
<!--核心 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<!--DAO层 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<!-- web层 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.6</version>
</dependency>
<!--Spring test -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.1.7.RELEASE</version>
</dependency>
<!-- DAO-MyBatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.3.0</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.3</version>
</dependency>
<!--mybatist 其他包-->
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>asm</groupId>
<artifactId>asm</artifactId>
<version>3.3.1</version>
</dependency>
<!--mybatis日志文件-->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.12</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
2 db.properties
jdbc.driver = com.mysql.jdbc.Driver
jdbc.url =jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8
jdbc.username =root
jdbc.password = root
3 log4j.properties
log4j.rootLogger=DEBUG,stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
二 原始dao方法
1 定义接口(User.java)
package edu.eurasia.dao;
import edu.eurasia.entity.UserBean;
public interface UserDao {
UserBean findUser(int id) throws Exception;
}
2 接口实现(UserImpl.java)
- 继承SqlSessionDaoSupport,使用getSqlSession获取sqlSession,不用手动注入sqlSessionFactory
package edu.eurasia.dao.impl;
import edu.eurasia.dao.User;
import edu.eurasia.entity.UserBean;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;
public class UserImpl extends SqlSessionDaoSupport implements User {
public UserBean findUserById(int id) throws Exception {
SqlSession sqlSession = this.getSqlSession();
UserBean userBean = sqlSession.selectOne("test.findUserById",id);
return userBean;
}
}
3 User.xml文件配置(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">
<select id="findUserById" parameterType="int" resultType="edu.eurasia.entity.UserBean">
SELECT * FROM user WHERE id=#{user.id}
</select>
</mapper>
4 配置文件引入mybatis配置文件(mybatis-config.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>
<mappers>
<mapper resource="mapper/User.xml"></mapper>
</mappers>
</configuration>
5 配置spring核心配置文件(applicationContext.xml)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
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.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!-- 配置数据库相关参数properties的属性:${url} -->
<context:property-placeholder location="classpath:db.properties" />
<!--配置c3p0连接池-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"></property>
<property name="jdbcUrl" value="${jdbc.url}"></property>
<property name="user" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<!--配置sqlSqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--注入mybatis核心配置文件-->
<property name="configLocation" value="mybatis-config.xml"></property>
<!--注入数据源-->
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--配置UserImpl,注入sqlSessionFactory-->
<bean id="userDao" class="edu.eurasia.dao.impl.UserImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>
</beans>
6 测试(UserText.java)
package edu.eurasia;
import edu.eurasia.dao.User;
import edu.eurasia.entity.UserBean;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class UserText {
private ApplicationContext applicationContext;
@Before
public void setUp()throws Exception{
//获取spring核心配置文件
applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
}
@Test
public void findUserById() throws Exception{
//根据id获取注入sqlSessionFactory的方法
User user = (User) applicationContext.getBean("userDao");
UserBean userBean = user.findUserById(1);
System.out.println(userBean);
}
}
三 mapper自动映射方法
1 方法一
(1) 定义mapper sql核心配置文件(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="edu.eurasia.dao.UserMapper">
<select id="findUserByIdMapper" parameterType="int" resultType="edu.eurasia.entity.UserBean">
SELECT * FROM user WHERE id=#{user.id}
</select>
</mapper>
((2) 定义接口(UserMapper.java)
package edu.eurasia.dao;
import edu.eurasia.entity.UserBean;
public interface UserMapper {
UserBean findUserByIdMapper(int id) throws Exception;
}
((3) 配置文件引入mybatis配置文件(mybatis-config.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>
<mappers>
<mapper resource="mapper/User.xml"></mapper>
<mapper resource="mapper/UserMapper.xml"></mapper>
</mappers>
</configuration>
((4) spring核心配置文件(applicationContext.xml)
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
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.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!-- 配置数据库相关参数properties的属性:${url} -->
<context:property-placeholder location="classpath:db.properties" />
<!--配置c3p0连接池-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"></property>
<property name="jdbcUrl" value="${jdbc.url}"></property>
<property name="user" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<!--配置sqlSqlSessionFactory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!--注入mybatis核心配置文件-->
<property name="configLocation" value="mybatis-config.xml"></property>
<!--注入数据源-->
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--配置UserImpl,注入sqlSessionFactory-->
<bean id="userDao" class="edu.eurasia.dao.impl.UserImpl">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></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">
<!--注入sqlSessionFactory-->
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
<!--给出需要扫描Dao接口包-->
<property name="mapperInterface" value="edu.eurasia.dao.UserMapper"></property>
</bean>
</beans>
((5) 测试(MapperText.java)
package edu.eurasia;
import edu.eurasia.dao.UserMapper;
import edu.eurasia.entity.UserBean;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MapperText {
private ApplicationContext applicationContext;
@Before
public void setUp()throws Exception{
applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
}
@Test
public void findUserById() throws Exception{
UserMapper userMapper = (UserMapper) applicationContext.getBean("userMapper");
UserBean userBean = userMapper.findUserByIdMapper(1);
System.out.println(userBean);
}
}
缺点
- MapperFactoryBean 需要针对每个mapper进行配置
2 方法 二
- 针对方法一存在问题,做以下改进
(1) 优化applicationContext.xml配置文件
- 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)
- 如果扫描多个包,每个包中间使用半角逗号分隔
<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="edu.eurasia.dao"></property>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>
(2) 测试
package edu.eurasia;
import edu.eurasia.dao.UserMapper;
import edu.eurasia.entity.UserBean;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MapperText {
private ApplicationContext applicationContext;
@Before
public void setUp()throws Exception{
applicationContext = new ClassPathXmlApplicationContext("classpath:applicationContext.xml");
}
@Test
public void findUserById() throws Exception{
UserMapper userMapper = (UserMapper) applicationContext.getBean("userMapper");
UserBean userBean = userMapper.findUserByIdMapper(3);
System.out.println(userBean);
}
}
总结
- spring整合mabatis,使用方法二也就是自动扫描时,理论是不需要在mybatis核心配置文件中引入sql配置文件的,可事实是不引入会报错(不明,待解决)
<?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>
<mappers>
<mapper resource="mapper/User.xml"></mapper>
<!--去掉引入sql文件-->
<!--<mapper resource="mapper/UserMapper.xml"></mapper>-->
</mappers>
</configuration>
问题解决2018-4-25
阐述
在eclipse中mapper文件和mapper.xml配置文件是在同一目录下,所以上述配置就可以实现mapper的动态代理。
但是,在idea中,所有的配置文件都是在resources资源文件下,就引起mapper文件和mapper.xml配置文件不在同一目录下,所以,就会出现上述错误。
解决
在spring-dao配置文件中,在配置SqlSessionFactory对象时,加入自动扫描mapper.xml的配置文件
<!-- 3.配置SqlSessionFactory对象 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 注入数据源 -->
<property name="dataSource" ref="dataSource" />
<!-- 注入mybatis核心配置文件:sqlMapConfig.xml -->
<property name="configLocation" value="classpath:mybatis/sqlMapConfig.xml" />
<!-- 扫描entity包 使用别名 -->
<property name="typeAliasesPackage" value="com.entity" />
<!-- 扫描sql配置文件:mapper需要的xml文件 -->
<property name="mapperLocations" value="classpath:mapper/*.xml" />
</bean>