Spring series [11. Integrate Mybatis]

11. Integrate Mybatis

step:

1. Import related jar packages

• junit
• my shoe
• mysql database
• spring-related
• aop weaving
• mybatis-spring integration package

2. Write the configuration file

3. Test

11.1, recall mybatis

1. Write entity class
2. Write a core configuration file
3. write interface
4. Write Mapper.xml
5. test

11.2、Mybatis-Spring

Official document : http://mybatis.org/spring/zh/getting-started.html

1. Write data source configuration

### spring-dao.xml
<!--  DataSource：使用Spring的数据源替换Mybatis的配置
        我们这里使用Spring提供的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=true&amp;useUnicode=true&amp;characterEncoding=UTF-8&amp;serverTimezone=UTC"/>
    <property name="username" value="root"/>
    <property name="password" value="123456"/>
</bean>

2. Write sqlSessionFactory configuration

### spring-dao.xml
<!-- 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/only/mapper/*.xml"/>
</bean>

Define the configuration file of mybatis

### mybatis_config.xml
<configuration>
    <typeAliases>
        <package name="com.only.pojo"/>
    </typeAliases>
</configuration>

3、sqlSessionTemplate

### spring-dao.xml
<!--  sqlSessionTemplate: 就是我们使用的SqlSession  -->
<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
    <!-- 只能使用构造器注入sqlSessionFactory，因为它没有set方法 -->
    <constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

4. It is necessary to add an implementation class to the interface

### UserMapperImpl.java
public class UserMapperImpl implements UserMapper {
    
    

    //在原来，我们所有的操作都使用sqlSession来执行，现在都是用SqlSessionTemplate
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
    
    
        this.sqlSession = sqlSession;
    }

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

## User.java
@Data
public class User {
    
    
    private int id;
    private String name;
    private String pwd;
}

## UserMapper.xml
<mapper namespace="com.only.mapper.UserMapper">
    
    <select id="selectUser" resultType="user">
        select * from mybatis.user;
    </select>

</mapper>

5. Inject the implementation class written by yourself into Spring

### applicationContext.xml
<import resource="spring-dao.xml"/>

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

6. Test

@Test
public void test() throws IOException {
    
    
    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    UserMapper mapper = context.getBean("userMapper", UserMapper.class);
    List<User> userList = mapper.selectUser();
    for (User user : userList) {
    
    
        System.out.println(user);
    }
}

7. Test results

Method 2: Instead of using sqlSessionTemplate directly, use SqlSessionDaoSupport to obtain SqlSession, and getSqlSession()you will get a SqlSessionTemplate by calling the method.

The steps are still as above, without configuring the sqlSessionTemplate in step 3, directly modify the implementation class for the interface in step 4 as follows:

### UserMapperImpl2.java
public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
    
    
  public List<User> selectUser() {
    
    
    return getSqlSession().getMapper(UserMapper.class).selectUser();
  }
}

5. Inject the implementation class written by yourself into Spring

### applicationContext.xml
<import resource="spring-dao.xml"/>
<bean id="userMapper" class="com.only.mapper.UserMapperImpl2">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>