[Java知识库]Spring 整合Mybatis的两种方式

12、整合Mybatis

1. 导入相关jar包

   • junit

     <dependency>
         <groupId>junit</groupId>
         <artifactId>junit</artifactId>
         <version>4.12</version>
     </dependency>
     

   • mybatis

     <dependency>
         <groupId>org.mybatis</groupId>
         <artifactId>mybatis</artifactId>
         <version>3.5.7</version>
     </dependency>
     

   • mysql数据库

     <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <version>5.1.47</version>
     </dependency>
     

   • spring相关的

     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-webmvc</artifactId>
         <version>5.3.9</version>
     </dependency>
     

     <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-jdbc</artifactId>
         <version>5.3.9</version>
     </dependency>
     

   • aop织入

     <dependency>
         <groupId>org.aspectj</groupId>
         <artifactId>aspectjweaver</artifactId>
         <version>1.9.7</version>
     </dependency>
     

   • mybatis-spring【new】

     <dependency>
         <groupId>org.mybatis</groupId>
         <artifactId>mybatis-spring</artifactId>
         <version>2.0.6</version>
     </dependency>
     

2. 编写配置文件

3. 测试

12.1、回忆Mybatis

1. 编写实体类

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

2. 编写核心配置文件

   <?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.kuang.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=true&amp;useUnicode=true&amp;characterEncoding=utf8"/>
                   <property name="username" value="root"/>
                   <property name="password" value="123456"/>
               </dataSource>
           </environment>
       </environments>
   
       <mappers>
           <package name="com.kuang.dao"/>
       </mappers>
   

3. 编写接口

   public interface UserMapper {
       public List<User> selectUser();
   }
   

4. 编写Maper.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.kuang.dao.UserMapper">
   
       <select id="selectUser" resultType="User">
           select * from user
       </select>
   

5. 测试

   @Test
   public void selectUser() throws IOException {
    
       String resource = "mybatis-config.xml";
       InputStream inputStream = Resources.getResourceAsStream(resource);
       SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
       SqlSession sqlSession = sqlSessionFactory.openSession();
    
       UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    
       List<User> userList = mapper.selectUser();
       for (User user: userList){
           System.out.println(user);
       }
    
       sqlSession.close();
   }
   

?

12.2、Mybatis-Spring

第一种方式

1. 编写数据源配置

   <!--DataSourceL: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
       -->
   <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;useUnicode=true&amp;characterEncoding=UTF-8"/>
       <property name="username" value="root"/>
       <property name="password" value="123456"/>
   </bean>
   

2. sqlSessionFactory

   <!--sqlSessionFactory-->
   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
       <!--必须要配上的数据源-->
       <property name="dataSource" ref="datasource" />
       <property name="configLocation" value="mybatis-config.xml"/>
       <!--原先要在mabatis配置文件中配置的东西-->
       <property name="mapperLocations" value="classpath:com/kuang/mapper/*.xml"/>
   </bean>
   

3. sqlSessionTemplate

   <!--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,因为他没有set方法-->
       <constructor-arg index="0" ref="sqlSessionFactory"/>
   </bean>
   

4. 需要给接口加实现类

   public class UserMapperImpl implements UserMapper{
       
       //我们的所有操作都使用sqlSession执行在原来，
       //现在都使用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();
       }
   }
   

5. 将自己写的实现类注入到Spring中

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

6. 测试

   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);
           }
       }
   }
   

整合实现的第二种方式

1. 新的实现类

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

2. 修改spring中的bean

   <bean id="userMapper2" class="com.kuang.mapper.UserMapperImpl2">
       <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
   </bean>
   

3. 测试类

   public class MyTest {
       @Test
       public void test(){
           ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
           UserMapper userMapper = context.getBean("userMapper2", UserMapper.class);
           for (User user : userMapper.selectUser()){
               System.out.println(user);
           }
       }
   }
   

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