将mybatis的功能整合到Spring中去
创建一个maven项目，配置maven并导入依赖
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>Spring-study</artifactId>
<groupId>com.xmn</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>spring-10-springmybatis</artifactId>
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.3.22</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.6</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
数据库的结构如下：
mybatis的配置文件，我们也可以通过Spring来配置。
配置文件内容如下：
<?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: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/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">
<!--DataSource:使用Spring的数据源替换mybatis配置
这里使用Spring的JDBC
-->
<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/mybatis?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</bean>
<!--得到sqlSessionFectory-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!--绑定mybatis配置文件-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="classpath*:com/xmn/mapper/*.xml"/>
</bean>
<!--利用了SqlSessionTemplate类，输入一个sqlSessionFectory，得到一个sqlSession
SqlSessionTemplate需要一个sqlSessionFectory参数，但是SqlSessionTemplate没有set方法，所以使用构造方法赋值。
-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
</beans>
UserMapper接口
package com.xmn.mapper;
import com.xmn.pojo.User;
import java.util.List;
public interface UserMapper {
List<User> getUserList();
}
创建UserMapper的实现类，
package com.xmn.mapper;
import com.xmn.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;
import java.util.List;
public class UserMapperImpl implements UserMapper{
private SqlSessionTemplate sqlSession;
public void setSqlSession(SqlSessionTemplate sqlSession) {
this.sqlSession = sqlSession;
}
public List<User> getUserList() {
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
return mapper.getUserList();
}
}
将UserMapperImpl注册到Spring中
<bean id="userMapper" class="com.xmn.mapper.UserMapperImpl">
<property name="sqlSession" ref="sqlSession"/>
</bean>
最后测试：
@Test
public void Test2(){
ApplicationContext context = new ClassPathXmlApplicationContext("applicationConfig.xml");
UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
List<User> userList = userMapper.getUserList();
for (User user : userList) {
System.out.println(user);
}
}
测试结果：
关于实现类，我们还有第二种实现方法。
通过继承 SqlSessionDaoSupport 类，可以通过getSqlSession方法直接得到sqlsession，代码如下：
package com.xmn.mapper;
import com.xmn.pojo.User;
import org.mybatis.spring.support.SqlSessionDaoSupport;
import java.util.List;
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{
public List<User> getUserList() {
return getSqlSession().getMapper(UserMapper.class).getUserList();
}
}
这样实现类中只需要一行代码就可以实现功能。
声明性事务
事务：要么都执行，要么都完蛋
但是在Spring中怎么实现事务呢？
在代码出现问题时，代码执行后，之前完成的操作并不会回滚，例如
public List<User> getUserList() {
User qwer = new User(2, "qwer", "13579");
insert(qwer);
del(4);
return getSqlSession().getMapper(UserMapper.class).getUserList();
}
/------------------------------------------------------------------------------
@Test
public void test3(){
ApplicationContext context = new ClassPathXmlApplicationContext("applicationConfig.xml");
UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
List<User> userList = userMapper.getUserList();
for (User user : userList) {
System.out.println(user);
}
}
因为在del的xml文件中留了错误，所以del函数不会执行，但是insert函数已经执行，并且不会回滚，导致了以下结果。
在Spring中，我们可以通过AOP实现事务回滚。
<!--配置声明式事务-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<constructor-arg ref="dataSource"/>
</bean>
<!--结合AOP实现事务织入-->
<!--配置事务传播特性 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
<!--配置事务切入-->
<aop:config>
<aop:pointcut id="txPointCut" expression="execution(* com.xmn.mapper.*。*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref ="txPointCut"/>
</aop:config>
再次运行之前的测试代码，运行后，因为del函数中的错误，数据回滚，数据库中没有插入，也没有删除。
