整合Mybatis

整合Mybatis

一、整合Mybatis

步骤

1. 导入相关jar包

   mybatis：
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis</artifactId>
       <version>3.4.6</version>
   </dependency>
   ​
   mysql：
           <dependency>
               <groupId>mysql</groupId>
               <artifactId>mysql-connector-java</artifactId>
               <version>8.0.23</version>
           </dependency>
   ​
   spring相关：
           <dependency>
               <groupId>org.springframework</groupId>
               <artifactId>spring-webmvc</artifactId>
               <version>5.3.4</version>
           </dependency>
           <dependency>
               <groupId>org.springframework</groupId>
               <artifactId>spring-jdbc</artifactId>
               <version>5.3.3</version>
           </dependency>
   ​
   aspectJ AOP织入器：
           <dependency>
               <groupId>org.aspectj</groupId>
               <artifactId>aspectjweaver</artifactId>
               <version>1.9.4</version>
           </dependency>
   ​
   mybatis-spring整合包：
           <dependency>
               <groupId>org.mybatis</groupId>
               <artifactId>mybatis-spring</artifactId>
               <version>2.0.6</version>
           </dependency>

2. 配置Maven静态资源过滤问题

   <build>
       <resources>
           <resource>
               <directory>src/main/resources</directory>
               <includes>
                   <include>**/*.properties</include>
                   <include>**/*.xml</include>
               </includes>
               <filtering>true</filtering>
           </resource>
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.properties</include>
                   <include>**/*.xml</include>
               </includes>
               <filtering>true</filtering>
           </resource>
       </resources>
   </build>

3. 编写配置文件

4. 代码实现

1.1 Mybatis-Spring学习

要和Spring一起使用Mybatis，需要在Spring应用上下文中定义两样东西：

• SqlSessionFactory

• 至少一个数据映射器类

在MyBatis-Spring中，可以使用SqlSessionFactoryBean来创建SqlSessionFactory。要配置这个工厂的bean，只需要在Spring配置中加入：

<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="datasource"/>
    <property name="configLocation" value="mybatis-config.xml"/>
    <property name="mapperLocations" value="classpath:com/aishimin/dao/UserMapper.xml"/>
</bean>

SqlSessionFactory需要一个DataSource（数据源）。

在基础的MyBatis中是通过SQLSessionFactoryBuilder来创建SQLSessionFactory的。在MyBatis-Spring中则是用过SQLSessionBean来创建。

SqlSessionFactory中有一个唯一的必要属性：用于JDBC的DataSource。

一个常用的属性是configLocation，他用来指定MyBatis的XML配置文件路径。通常在其内配置<setting> 和<typeAliases>

SQLSessionTemplate是MyBatis-Spring的核心。作为SqlSession的一个实现，也就是说相当于使用它代替SqlSession。可以使用SqlSessionFactory作为构造方法的参数来创建SqlSessionTemplate对象。

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

现在就可以将这个bean注入到java类中。

public class UserMapperImpl implements UserMapper{
​
    private SqlSessionTemplate sqlSession;
​
    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

接下来注入SqlSessionTemplate

<bean id="UserMapper" class="com.aishimin.dao.UserMapperImpl">
    <property name="sqlSession" ref="sqlSession"/>
</bean>

整合实现一：

1. 引入Spring配置文件spring-dao.xml

2. 配置数据源替换mybatis的数据源

   <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=utf8"/>
       <property name="username" value="root"/>
       <property name="password" value="123456"/>
   </bean>

3. 配置SqlSessionFactory，关联Mybatis

   <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
       <property name="dataSource" ref="datasource"/>
       <property name="configLocation" value="mybatis-config.xml"/>
       <property name="mapperLocations" value="classpath:com/aishimin/dao/UserMapper.xml"/>
   </bean>

4. 注册sqlSessionTemplate，关联SqlSessionFactory

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

5. 增加Dao接口的实现类，私有化sqlSessionTemplate

   public class UserMapperImpl implements UserMapper{
   ​
       private SqlSessionTemplate sqlSession;
   ​
       public void setSqlSession(SqlSessionTemplate sqlSession) {
           this.sqlSession = sqlSession;
       }
   ​
       @Override
       public List<User> getUserList() {
           UserMapper mapper = sqlSession.getMapper(UserMapper.class);
           return mapper.getUserList();
       }
   }

    

6. 注册bean实现

   <bean id="UserMapper" class="com.aishimin.dao.UserMapperImpl">
       <property name="sqlSession" ref="sqlSession"/>
   </bean>

7. 测试

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

整合方式二

1. 新建UserMapperImpl2

   public class UserMapperImpl2 extends SqlSessionDaoSupport implements UserMapper {
       @Override
       public List<User> getUserList() {
           UserMapper userMapper = getSqlSession().getMapper(UserMapper.class);
           return userMapper.getUserList();
       }
   }

2. 修改bean配置

   <bean id="UserMapper2" class="com.aishimin.dao.UserMapperImpl2">
       <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
   </bean>

3. 测试

   public class MyTest {
       @Test
       public void test() {
           ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
           UserMapper mapper = context.getBean("UserMapper2", UserMapper.class);
           for(User user:mapper.getUserList()){
               System.out.println(user);
           }
       }
   }