12.整合Mybatis

12.整合Mybatis

12.1.步骤：

1.导入相关jar包

• junit
• mybatis
• mysql数据库
• spring相关的
• aop织入
• mybatis-spring【new】

2.编写配置文件

3.测试

12.2.回忆Mybatis

• 编写实体类
• 编写核心配置文件
• 编写接口
• 编写Mapper.xml
• 编写utils
• 测试类

12.3.Mybatis-spring

1.编写数据源配置

ApplicationContext-Mybatis.xml

<?xml version="1.0" encoding="UTF8"?>
<beans xmlns="<http://www.springframework.org/schema/beans>"
       xmlns:xsi="<http://www.w3.org/2001/XMLSchema-instance>"
       xsi:schemaLocation="<http://www.springframework.org/schema/beans>
        <https://www.springframework.org/schema/beans/spring-beans.xsd>
        ">
    <!--DataSource：使用Spring的数据源替换Mybatis的配置  c3p0 dbcp druid
    我们这里使用Spring提供的JDBC:org.springframework.jdbc.datasource.DriverManagerDataSource
    -->
    <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&amp;userUnicode=ture&amp;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/itxiaofei/mapper/*.xml"/>
    </bean>

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

ApplicationContext.xml

<?xml version="1.0" encoding="UTF8"?>
<beans xmlns="<http://www.springframework.org/schema/beans>"
       xmlns:xsi="<http://www.w3.org/2001/XMLSchema-instance>"
       xsi:schemaLocation="<http://www.springframework.org/schema/beans>
        <https://www.springframework.org/schema/beans/spring-beans.xsd>
        ">

    <!--导入Mybatis-spring配置文件-->
    <import resource="ApplicationContext-Mybatis.xml"/>
    <!--注入UserMapperImpl-->
    <bean id="UserMapper" class="com.itxiaofei.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
    </bean>
</beans>

2.sqlSessionFactory

3.sqlSessionTemplate

4.需要给接口加实现类【***MappeImpl】

public class UserMapperImpl implements  UserMapper{

    //我们的所有操作，都使用sqlSession来执行，
    // 现在都是用sqlSessionTemplate来执行
    private SqlSessionTemplate sqlSessionTemplate;

    public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
        this.sqlSessionTemplate = sqlSessionTemplate;
    }

    public List<User> selectUser() {
        UserMapper mapper = sqlSessionTemplate.getMapper(UserMapper.class);
        List<User> user = mapper.selectUser();
        return user;
    }
}

5.将自己写的实现类注入到Spring中

<bean id="UserMapper" class="com.itxiaofei.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
</bean>

6.测试即可

@Test
    public void selectUser(){
        ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml");
        UserMapper userMapper = context.getBean("UserMapper", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }
    }

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。

public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper{

    public List<User> selectUser() {
//        SqlSession sqlSession = getSqlSession();
//        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
//        List<User> user = mapper.selectUser();
//        return user;
//        以下为精简版
        return getSqlSession().getMapper(UserMapper.class).selectUser();
    }
}