spring-mybatis笔记
一、Spring整合MyBatis的三个关键点
- (1)将MyBatis的DataSource交给Spring IoC容器创建并管理，使用第三方数据库连接池(Druid，C3P0等)代替MyBatis内置的数据库连接池
- (2)将MyBatis的SqlSessionFactory交给Spring IoC容器创建并管理，使用spring-mybatis整合jar包中提供的SqlSessionFactoryBean类代替项目中的MyBatisUtil工具类
- (3)将MyBatis的接口代理方式生成的实现类，交给Spring IoC容器创建并管理
1、导入相关jar包
lombok---junit---mybatis---mysql数据库---spring相关---aop织入器---mybatis-psring整合包【重点】
<dependencies>
<!--juint测试-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<!--MySQL驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<!--mybatis核心jar包-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.1.9.RELEASE</version>
</dependency>
<!--spring操作数据库的话，还需要一个spring-jdbc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.1.9.RELEASE</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.13</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.2</version>
</dependency>
<!--lombok工具-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.10</version>
</dependency>
<dependency>
<groupId>org.example</groupId>
<artifactId>spring-anno</artifactId>
<version>1.0-SNAPSHOT</version>
<scope>compile</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-tx -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>5.3.12</version>
</dependency>
</dependencies>
<!--配置资源过滤问题-->
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
2、mybatis层编写
1、编写实体类
@Data
public class user {
private int id;
private String name;
private String pwd;
}
2、编写mybatis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>
<typeAliases>
<package name="com.test.pojo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=utf8"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</dataSource>
</environment>
</environments>
<mappers>
<package name="com.test.dao"/>
</mappers>
</configuration>
3、编写UserMapper接口
public interface UserMapper {
@Select("select * from mybatis.user")
public List<user> selectUser();
}
4、编写UserMapper.xml配置文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.test.mapper.UserMapper">
</mapper>
5、测试
@Test
public void test() throws IOException {
String resources = "mybatis-config.xml";
InputStream in = Resources.getResourceAsStream(resources);
SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);
SqlSession sqlSession = sessionFactory.openSession(true);
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
List<user> userList = mapper.selectUser();
for (user user : userList) {
System.out.println(user);
}
sqlSession.close();
}
3、spring整合操作
1、引入Spring配置文件 spring-dao.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: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">
</beans>
2、配置比数据源替换mybatis的数据源
<!--DataSource:使用Spring的数据源替换MyBatis的配置， c3p0 dbcp druid
这里使用spring提供的jdbc，org.springframework.jdbc.datasource
-->
<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"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</bean>
3、配置SqlSessionFactory，关联MyBatis
<!--SqlSessionFactory-->
<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/test/mapper/*.xml"/>
</bean>
4、注册sqlSessionTemplate，关联sqlSessionFactory
<!--org.mybatis.spring.SqlSessionTemplate-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
<!--只能使用构造器注入sqlsessionFactory，因为没有set方法-->
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
5、需要UserMapper接口的UserMapperImpl 实现类，私有化sqlSessionTemplate
public class UserMapperImpl implements UserMapper{
//我们的所有操作，都使用sqlSession来执行，在原来，现在都使用SqlSessionTemplate
private SqlSessionTemplate sqlSession;
public void setSqlSession(SqlSessionTemplate sqlSession) {
this.sqlSession = sqlSession;
}
@Override
public List<user> selectUser() {
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
return mapper.selectUser();
}
}
6、将自己写的实现类，注入到Spring配置文件中。
<bean id="userMapper" class="com.test.mapper.UserMapperImpl">
<property name="sqlSession" ref="sqlSession"/>
</bean>
完整的spring-dao.xml文件
<?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的配置， c3p0 dbcp druid
这里使用spring提供的jdbc，org.springframework.jdbc.datasource
-->
<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"/>
<property name="username" value="root"/>
<property name="password" value="123456"/>
</bean>
<!--SqlSessionFactory-->
<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/test/mapper/*.xml"/>
</bean>
<!--org.mybatis.spring.SqlSessionTemplate-->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
<!--只能使用构造器注入sqlsessionFactory，因为没有set方法-->
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>
<bean id="userMapper" class="com.test.mapper.UserMapperImpl">
<property name="sqlSession" ref="sqlSession"/>
</bean>
</beans>
6、测试
@Test
public void test() throws IOException {
ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
for (com.test.pojo.user user : userMapper.selectUser()) {
System.out.println(user);
}
}
结果成功输出！现在我们的Mybatis配置文件的状态！发现都可以被Spring整合！
<?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>
<typeAliases>
<package name="com.test.pojo"/>
</typeAliases>
<mappers>
<mapper class="com.test.mapper.UserMapper"/>
</mappers>
</configuration>
整合实现二：
dao继承Support类 , 直接利用 getSqlSession() 获得 , 然后直接注入SqlSessionFactory . 比起整合方式一 , 不需要管理SqlSessionTemplate , 而且对事务的支持更加友好 . 可跟踪源码查看。mybatis-spring1.2.3版以上的才有这个
1、将我们上面写的UserMapperImpl修改一下
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
// @Override
// public List<user> selectUser() {
// SqlSession sqlSession = getSqlSession();
// UserMapper mapper = sqlSession.getMapper(UserMapper.class);
// return mapper.selectUser();
// }
@Override
public List<user> selectUser() {
return getSqlSession().getMapper(UserMapper.class).selectUser();
}
}
2、注入到spring配置文件中
<bean id="userMapper2" class="com.test.mapper.UserMapperImpl2">
<property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
3、测试
@Test
public void test() throws IOException {
ApplicationContext context = new ClassPathXmlApplicationContext("aplicationContext.xml");
UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
for (com.test.pojo.user user : userMapper.selectUser()) {
System.out.println(user);
}
}
基本操作
1、编写数据源
2、sqlsessionFactory
3、sqlsessionTemplate
4、需要给接口加实现类
5、测试
6、将自己写的实现类，注入到spring中
1、导入Lombok
2、创建实体类
3、创建mapper
4、创建mapper.xml
5、创建mapper实现类
6、完成sqlsession注册
事务
一个使用 MyBatis-Spring 的其中一个主要原因是它允许 MyBatis 参与到 Spring 的事务管理中。而不是给 MyBatis 创建一个新的专用事务管理器，MyBatis-Spring 借助了 Spring 中的 DataSourceTransactionManager 来实现事务管理
- 声明式事务在spring-dao.xml中配置声明式事务
<!--配置声明式事务-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<constructor-arg ref="dataSource" />
</bean>
<!--结合AOP实现事务的织入-->
<!--配置事务的类-->
<!--配置事务通知-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<!--给哪些方法配置事务-->
<tx:attributes>
<tx:method name="add" propagation="REQUIRED"/>
<tx:method name="delete" propagation="REQUIRED"/>
<tx:method name="update" propagation="REQUIRED"/>
<tx:method name="query" read-only="true"/>
<tx:method name="*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
<!--配置事务切入-->
<aop:config>
<aop:pointcut id="txPointCut" expression="execution(* com.test.mapper.*.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
</aop:config>
- 编程式事务（不想看,哭）
思考：
为什么需要事务：
- 如果不配置事务，可能存在数据提交不一致的情况
- 如果我们不在spring中配置声明式事务，就需要在代码中手动配置事务！
- 事务在项目开发中十分重要，涉及到数据的一致性和完整性问题。
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