SqlSession
在 MyBatis 中,你可以使用 SqlSessionFactory 来创建 SqlSession。一旦你获得一个 session 之后,你可
以使用它来执行映射了的语句,提交或回滚连接,最后,当不再需要它的时候,你可以关闭 session。使
用 MyBatis-Spring 之后,你不再需要直接使用 SqlSessionFactory 了,因为你的 bean 可以被注入一个线
程安全的 SqlSession,它能基于 Spring 的事务配置来自动提交、回滚、关闭 session。
SqlSessionDaoSupport
SqlSessionDaoSupport 是一个抽象的支持类,用来为你提供 SqlSession。调用 getSqlSession() 方法你会
得到一个 SqlSessionTemplate,之后可以用于执行 SQL 方法。
案例
导包
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
<!--连接数据库-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.17</version>
</dependency>
<!--使用mybatis框架-->
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>
<!-- 直接导入spring-webmvc会自动帮我们导入spring-aop,spring-beans,
spring-context,spring-core,spring-expression,spring-web的依赖jar包 -->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<!-- 配置声明式事务 -->
<!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.10</version>
</dependency>
<!-- spring-mybatis -->
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring Spring整合Mybatis需要的整合包 -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.20</version>
<scope>provided</scope>
</dependency>
1.User
@Data
public class User {
private int id;
private String name;
private String pwd;
}
2.UserMapper
public interface UserMapper {
public List<User> selectUser();
}
3.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="com.tt.mapper.UserMapper">
<select id="selectUser" resultType="user">
select* from mybatis.user;
</select>
</mapper>
4.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>
<typeAliases>
<package name="com.tt.pojo"/>
</typeAliases>
</configuration>
5.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" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
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 http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd">
<!--DataSource:使用Spring的数据源替换Mybatis的配置c3pe dbcp druid
我们这里使用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&autoReconnect=true"/>
<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Mabatis配置文件-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="classpath:com/tt/mapper/*.xml"/>
</bean>
</beans>
6.UserMapperImpl2
public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper {
@Override
public List<User> selectUser() {
return getSqlSession().getMapper(UserMapper.class).selectUser();
}
}
7.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: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">
<import resource="spring-dao.xml"/>
<!---->
<bean id="userMapper" class="com.tt.mapper.UserMapperImpl" >
<property name="sqlSessionFactory" ref= "sqlSessionFactory" />
</bean>
</beans>
8.MyTest
public class MyTest {
@Test
public void test() {
ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
for (User user : userMapper.selectUser()) {
System.out.println(user);
}
}
}