spring——整合Mybatis

一、Mybatis整合spring

步骤:

1. 导入相关jar包
   • junit
   • mybatis
   • mysql数据库
   • spring-webmvc
   • aop织入
   • mybatis-spring
   • spring-jdbc(spring的事务管理器,也可以用druid等的代替)
2. 编写配置文件
3. 测试

1.1 回忆mybatis

1. 编写实体类
2. 编写核心配置文件
3. 编写接口
4. 编写Mapper.xml
5. 测试

1.2 整合方式一

注意版本限制:

1. dataSource(这里配置使用Spring的数据源替换Mybatis的配置)

   <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
       <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
       <property name="url" value="jdbc:mysql://localhost:3306/dailyClick-test?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf-8"/>
       <property name="username" value="1111"/>
       <property name="password" value="1111"/>
   </bean>
   

   注:Mybatis有默认的数据源(连接池),但是是可以替换的

2. sqlSessionFactory配置

   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
       <property name="dataSource" ref="dataSource" />
       <!--        绑定配置文件地址和mapper地址-->
       <property name="configLocation" value="classpath:mybatis-config.xml"/>
       <property name="mapperLocations" value="classpath:com/guan/dao/*.xml"/>
   </bean>
   

   注意:

   • 需要配置数据源
   • 需要绑定配置文件地址和mapper地址,注意这里的路径使用classpath路径
   • 由于mapper等信息被转移到<bean>中,不能重复配置(如:<mapper>),否则会报错;mybatis-config.xml配置文件通常留<typeAlias>和<settings>

3. 与在原来的mybatis不同,整合后需要有一个接口的实现类,且接口的方法需要通过sqlSessionTemplate实现(有利于bean的注册和管理,这个sqlSessioinTemplate是线程安全的)

   sqlSessionTemplate配置

   <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
       <constructor-arg index="0" ref="sqlSessionFactory"/>
   </bean>
   

   注:由于sqlSessionTemplate没有set方法,只有构造函数,所以通过<constructor>标签注入

4. 实现类:与mybatis元素代码不同,接口类需要实现且接口的方法通过sqlSessionTemplate实现

   public class UserMapperImpl implements UserMapper {
       SqlSessionTemplate sqlSession;
   
       public void setSqlSession(SqlSessionTemplate sqlSession) {
           this.sqlSession = sqlSession;
       }
   
       public List<UserBean> getUserList() {
           UserMapper mapper = sqlSession.getMapper(UserMapper.class);
           return mapper.getUserList();
       }
   }
   

   <bean id="userMapper" class="com.guan.dao.UserMapperImpl">
       <property name="sqlSession" ref="sqlSession"/>
   </bean>
   

5. 测试

   public class MyTest {
       public static void main(String[] args) throws IOException {
           ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
           UserMapperImpl userMapperImpl = context.getBean("userMapper", UserMapperImpl.class);
           List<UserBean> userList = userMapperImpl.getUserList();
           for (UserBean userBean : userList) {
               System.out.println(userBean);
           }
       }
   }
   

   注:

   (1).mybatis的配置文件(指的是和spring注册的那一部分),最好通过import引入ApplicationiContext中,这样spring配置文件的结构可以区分开

   (2).xxxTemplate是spring特有的模板类

1.3 整合方式二

注:SqlSessionDaoSupport:抽象类,可以通过SqlSessionFactory获得一个SqlSessionTemplate.所以该方法相对于第一种方法增加了一个抽象类,减少了一个配置SqlSessionTemplate的步骤

1. 环境搭建:

   接口:

   public interface UserMapper1 {
       List<UserBean> getUserList();
   }
   

   xml实现

   <?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.guan.dao.UserMapper1">
       <select id="getUserList" resultType="userBean">
           SELECT  * FROM  user;
       </select>
   </mapper>
   

   实体类:

   public class UserMapper1Impl extends SqlSessionDaoSupport implements UserMapper1{
       public List<UserBean> getUserList() {
           return getSqlSession().getMapper(UserMapper1.class).getUserList();
       }
   }
   

2. xml配置(在上文的前文的基础上配置)

   <bean id="userMapper1" class="com.guan.dao.UserMapper1Impl">
       <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
   </bean>
   

3. 测试:

       public static void main(String[] args) throws IOException {
           ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
           UserMapper1Impl userMapperImpl = context.getBean("userMapper1", UserMapper1Impl.class);
           List<UserBean> userList = userMapperImpl.getUserList();
           for (UserBean userBean : userList) {
               System.out.println(userBean);
           }
       }
   

二、spring中的事物管理

1. 编程式事务:将事务管理代码嵌到业务方法中控制事务的提交和回滚

   缺点:使业务逻辑中包含额外的事务管理代码

2. 声明式事物:使用AOP

   (1).搭建环境:

   接口

   public interface UserMapper1 {
       List<UserBean> getUserList();
       void insert(UserBean user);
       void delete(String UId);
   }
   

   mapper:

   <insert id="insert" parameterType="userBean">
       INSERT  INTO user(UId,UName,USet,UAuth,UPassword,UState) VALUES(#{UId},#{UName},#{USet},#{UAuth},#{UPassword},#{UState});
   </insert>
   
   <delete id="delete" parameterType="string">
       DELETEs FROM user WHERE UId = #{UId};
   </delete>
   

   注:可以看到我这里的"DELETEs"是错误的写法

   编写实体类:

   public class UserMapper1Impl extends SqlSessionDaoSupport implements UserMapper1{
       public List<UserBean> getUserList() {
           insert(new UserBean("6666666666","淀真嗣",1,0,"123456",1));
           delete("3180421016");
           return getSqlSession().getMapper(UserMapper1.class).getUserList();
       }
   
       public void insert(UserBean user) {
           getSqlSession().getMapper(UserMapper1.class).insert(user);
       }
   
       public void delete(String UId) {
           getSqlSession().getMapper(UserMapper1.class).delete(UId);
       }
   }
   

   注:getUserList中添加了insert和delete方法,且delete方法是错误的.如果没有事务,则插入可以完成;如果有事务,则插入无法完成

   (2).导入事务相关的xml头文件约束,创建DataSourceTransaction对象以开启事务,配置事务通知,结合AOP实现事务的织入

   <?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:tx="http://www.springframework.org/schema/tx"
          xmlns:aop="http://www.springframework.org/schema/aop"
          xsi:schemaLocation="http://www.springframework.org/schema/beans
           https://www.springframework.org/schema/beans/spring-beans.xsd
           http://www.springframework.org/schema/tx
           https://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd">
   
       <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
           <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
           <property name="url" value="jdbc:mysql://47.100.90.132:3306/dailyClick-test?useSSL=false&amp;useUnicode=true&amp;characterEncoding=utf-8"/>
           <property name="username" value="root"/>
           <property name="password" value="aguan123"/>
       </bean>
   
       <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
           <property name="dataSource" ref="dataSource" />
   <!--        bind mybatis-config.xml and userMapper.xml-->
           <property name="configLocation" value="classpath:mybatis-config.xml"/>
           <property name="mapperLocations" value="classpath:com/guan/dao/*.xml"/>
       </bean>
   
       <bean id="userMapper1" class="com.guan.dao.UserMapper1Impl">
           <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
       </bean>
   
   <!--    配置声明式事务-->
       <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
           <property name="dataSource" ref="dataSource"/>
       </bean>
   
   <!--    配置事务通知-->
       <tx:advice id="txAdvice" transaction-manager="transactionManager">
           <tx:attributes>
               <tx:method name="getUserList" propagation="REQUIRED"/>
           </tx:attributes>
       </tx:advice>
   
   <!--    结合AOP织入事务-->
       <aop:config>
           <aop:pointcut id="point" expression="execution(* com.guan.dao.*.*(..))"/>
   <!--        <aop:advisor advice-ref="txAdvice" pointcut-ref="point"/>-->
       </aop:config>
   
   </beans>
   

   注:<tx:method name="getUserList" propagation="REQUIRED"/>的propagation属性表示对这些方法怎样使用事务,如:REQUIRED表示支持当前事务，如果当前没有事务，就新建一个事务 (Default)

   (3).测试

   public class MyTest {
   
       public static void main(String[] args) throws IOException {
           ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
           UserMapper1 userMapperImpl = context.getBean("userMapper1", UserMapper1.class);
           List<UserBean> userList = userMapperImpl.getUserList();
           for (UserBean userBean : userList) {
               System.out.println(userBean);
           }
       }
   }
   

   注意:由于使用了AOP,这里UserMapper1 userMapperImpl = context.getBean("userMapper1", UserMapper1.class)的返回类型必须为interface类型,而不是实体类型