[11] Spring simple integration of Mybatis

12. Integrate Mybatis

step:

1. Configure maven dependencies
   • junit
   • mybatis
   • mysql database
   • spring related
   • aop weaving
   • mybatis-spring [new package]
2. Write configuration file
3. test

12.1 Memories of mybatis

1. Writing entity classes

   StudentMapper.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.kuber.mapper.StudentMapper">
       <select id="studentQuery" resultType="Student">
           select * from student;
       </select>
   </mapper>
   

2. Write core configuration files

   mybatis-config.xml file

   <?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>
   
       <properties resource="db.properties"/>
   
       <typeAliases>
           <package name="com.kuber.pojo"/>
       </typeAliases>
   
       <environments default="development">
           <environment id="development">
               <transactionManager type="JDBC"/>
               <dataSource type="POOLED">
                   <property name="driver" value="${driver}"/>
                   <property name="url" value="${url}"/>
                   <property name="username" value="${username}"/>
                   <property name="password" value="${password}"/>
               </dataSource>
           </environment>
       </environments>
       <mappers>
           <mapper resource="com/kuber/mapper/StudentMapper.xml"/>
       </mappers>
   </configuration>
   

   db.properties configuration file

   driver=com.mysql.cj.jdbc.Driver
   url=jdbc:mysql://localhost:3306/bigdata?serverTimezone=UTC&userSSL=false&useUnicode=true&characterEncoding=UTF-8
   username=root
   password=root
   

3. Write interface

   StudentMapper interface class

   public interface StudentMapper {
         
         
   
       public List<Student> studentQuery();
   }
   

4. Write mapper.xml

   StudentMapper.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.kuber.mapper.StudentMapper">
       <select id="studentQuery" resultType="Student">
           select * from student;
       </select>
   </mapper>
   

5. test

   @Test
   public void test1() throws IOException {
         
         
       String resources = "mybatis-config.xml";
       InputStream is = Resources.getResourceAsStream(resources);
       SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
       SqlSession sqlSession = sessionFactory.openSession(true);
   
   
       StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
       List<Student> students = mapper.studentQuery();
       for (Student student : students) {
         
         
           System.out.println(student);
       }
   }
   

6. result

   

12.2、Mybatis-spring

1. Write data source configuration

2. sqlSessionFactory

3. sqlSessionTemplate

   1-3 is integrated as follows, 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"
          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-->
       <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
           <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
           <property name="url" value="jdbc:mysql://localhost:3306/bigdata?serverTimezone=UTC&amp;userSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
           <property name="username" value="root"/>
           <property name="password" value="root"/>
       </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="mybatis-config.xml"/>
           <property name="mapperLocations" value="classpath:com/kuber/mapper/StudentMapper.xml"/>
       </bean>
   
       <!--SqlSessionTemplate:就是我们使用的sqlSession-->
       <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
           <constructor-arg index="0" ref="sqlSessionFactory"/>
       </bean>
   
   
   </beans>
   

   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"
          xsi:schemaLocation="http://www.springframework.org/schema/beans
           https://www.springframework.org/schema/beans/spring-beans.xsd">
   
       <import resource="spring-dao.xml"/>
   
       <!--老方法，重点掌握-->
       <bean id="studentMapper" class="com.kuber.mapper.StudentMapperImpl">
           <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
       </bean>
   
       <!--新方法，接口实现类中继承SqlSessionDaoSupport类-->
       <bean id="studentMapper2" class="com.kuber.mapper.StudentMapperImpl2">
           <property name="sqlSessionFactory" ref="sqlSessionFactory" />
       </bean>
   
   
   </beans>
   

4. Need to add implementation class to interface【】

   The interface implementation class of the old method (focus on mastering):

   public class StudentMapperImpl implements StudentMapper{
         
         
   
       private SqlSessionTemplate sqlSessionTemplate;
   
       public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
         
         
           this.sqlSessionTemplate = sqlSessionTemplate;
       }
   
       @Override
       public List<Student> studentQuery() {
         
         
           StudentMapper mapper = sqlSessionTemplate.getMapper(StudentMapper.class);
           return mapper.studentQuery();
       }
   }
   

   The interface implementation class of the new method (this can be simpler)

   public class StudentMapperImpl2 extends SqlSessionDaoSupport implements StudentMapper{
         
         
       @Override
       public List<Student> studentQuery() {
         
         
           return getSqlSession().getMapper(StudentMapper.class).studentQuery();
       }
   }
   

5. Inject your own implementation class into Spring

   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"
          xsi:schemaLocation="http://www.springframework.org/schema/beans
           https://www.springframework.org/schema/beans/spring-beans.xsd">
   
       <import resource="spring-dao.xml"/>
   
       <!--老方法，重点掌握-->
       <bean id="studentMapper" class="com.kuber.mapper.StudentMapperImpl">
           <property name="sqlSessionTemplate" ref="sqlSessionTemplate"/>
       </bean>
   
       <!--新方法，接口实现类中继承SqlSessionDaoSupport类-->
       <bean id="studentMapper2" class="com.kuber.mapper.StudentMapperImpl2">
           <property name="sqlSessionFactory" ref="sqlSessionFactory" />
       </bean>
   
   
   </beans>
   

6. Just test and use

   Test of the old method:

   @Test
   public void test2(){
         
         
       ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
       StudentMapper studentMapper = applicationContext.getBean("studentMapper", StudentMapper.class);
       for (Student student : studentMapper.studentQuery()) {
         
         
           System.out.println(student);
       }
   }
   

   Testing of the new method:

   @Test
   public void test3(){
         
         
       ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
       StudentMapper studentMapper = applicationContext.getBean("studentMapper2", StudentMapper.class);
       for (Student student : studentMapper.studentQuery()) {
         
         
           System.out.println(student);
       }
   
   }
   

7. result