12、整合mybatis

步骤：

1. 导入相关jar包
   • junit
   • mybatis
   • mysql
   • spring
   • aop
   • mybatis-spring【new】
2. 编写配置文件
3. 测试

12.1、回忆mybatis

1. 编写实体类

   public class User {
       private int id;
       private String name;
       private String password;
   
       public User() {
       }
   
       public User(int id, String name, String password) {
           this.id = id;
           this.name = name;
           this.password = password;
       }
   }	
   

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核心配置文件-->
   <configuration>
       <typeAliases>
           <package name="com.xiao.pojo"/>
       </typeAliases>
       <environments default="development">
           <environment id="development">
               <transactionManager type="JDBC"/>
               <dataSource type="POOLED">
                   <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                   <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                   <property name="username" value="root"/>
                   <property name="password" value="12345678"/>
               </dataSource>
           </environment>
       </environments>
   
       <mappers>
           <mapper class="com.xiao.mapper.UserMapper"/>
       </mappers>
   </configuration>
   

3. 编写接口

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

4. 编写mapper.xml

   <?xml version="1.0" encoding="UTF-8" ?>
   <!DOCTYPE mapper
           PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
           "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
   
   <mapper namespace="com.xiao.mapper.UserMapper">
       <select id="selectUser" resultType="user">
           select  * from mybatis.user;
       </select>
   </mapper>
   

5. 测试

   public class MyTest {
       @Test
       public void test() throws IOException {
           String resources = "mybatis-config.xml";
           InputStream in = Resources.getResourceAsStream(resources);
           SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(in);
           SqlSession sqlSession = sessionFactory.openSession(true);
           UserMapper mapper = sqlSession.getMapper(UserMapper.class);
           List<User> users = mapper.selectUser();
           for (User user : users) {
               System.out.println(user);
           }
   
       }
   }
   

12.2、Mybatis-spring

1. 编写数据源配置

   <!--DataSource：使用mybatis的数据源替换mybatis的配置  c3p0   dbcp
   这里我们使用spring提供的jdbc
   -->
   <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/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
       <property name="username" value="root"/>
       <property name="password" value="12345678"/>
   </bean>
   

2. sqlsessionfactory

   <!--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/xiao/mapper/UserMapper.xml"/>
   </bean>
   

3. sqlsessionTemplate

   <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
       <!--只能使用构造器注入，因为没有set方法-->
       <constructor-arg ref="sqlSessionFactory"/>
   

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来执行，在原来，现在都是用SqlSessionTemplate
       private SqlSessionTemplate sqlSessionTemplate;
   
       public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
           this.sqlSessionTemplate = sqlSessionTemplate;
       }
   
       @Override
       public List<User> selectUser() {
           UserMapper mapper = sqlSessionTemplate.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.xiao.mapper.UserMapperImpl">
       <property name="sqlSessionTemplate" ref="sqlSession"/>
   </bean>
   

6. 测试使用

   public class MyTest {
       @Test
       public void test() throws IOException {
           ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
           UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
           List<User> users = userMapper.selectUser();
           for (User user : users) {
               System.out.println(user);
           }
       }
   }