Spring整合Mybatis

之间简单配置过SqlSessionFactory，但这并不是正规的整合方式，MyBatis提供了mybatis-spring.jar专门用于两大框架的整合

 Spring整合Mybatis的步骤：

• 导入MyBatis整合Spring的相关坐标

 <dependency>
      <groupId>org.springframeworkgroupId>
      <artifactId>spring-jdbcartifactId>
      <version>5.2.5.RELEASEversion>
    dependency>
    <dependency>
      <groupId>org.mybatisgroupId>
      <artifactId>mybatis-springartifactId>
      <version>2.0.4version>
    dependency>

• 编写Mapper和Mapper.xml

• 配置SqlSessionFactory和MapperScannerConfigurer

    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource">property>
    bean>
 
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.xfy.mapper">property>
 
    bean>
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver">property>
        <property name="url" value="jdbc:mysql:///book?useSSL=false&useServerPrepStmts=true">property>
        <property name="username" value="root">property>
        <property name="password" value="1234">property>
    bean>
 
 
  <bean id="userService"  class="com.xfy.service.impl.UserServiceImpl">
       <property name="userMapper" ref="userMapper">property>
    bean>

•  编写测试代码

    public static void main(String[] args) throws ParseException, IOException {
        ClassPathXmlApplicationContext applicationContext=new ClassPathXmlApplicationContext("ApplicationContext.xml");
        UserService userService = applicationContext.getBean("userService", UserService.class);
        userService.show();
 
        UserMapper userMapper = applicationContext.getBean("userMapper", UserMapper.class);
        for (User user : userMapper.SelectAll()) {
            System.out.println(user);
        }
    }
 
 
 
public class UserServiceImpl implements UserService, BeanNameAware {
    private UserDao userDao;
    private UserMapper userMapper;
    String Name;
 
    public void setUserMapper(UserMapper userMapper) {
        this.userMapper = userMapper;
    }
    public void show() {
        List users = userMapper.SelectAll();
        for (User user : users) {
            System.out.println(user);
        }
    }
    
    
    
    
    
    public interface UserMapper {
    List SelectAll();
}

 

Spring整合MyBatis的原理剖析

整合包里提供了一个SqlSessionFactoryBean和一个扫描Mapper的配置对象，SqlSessionFactoryBean一旦实例化，就开始扫描Mapper并通过动态代理产生Mapper的实现类，存储到Spring容器中，相关类：

• SqlSessionFactory：需要进行配置，用于提供SqlSessionFactory

• MapperSacnnerConfigurer:需要进行配置，用于扫描指定mapper注册BeanDefinition

• MapperFactoryBean：Mapper的FactoryBean，获得指定Mapper时调用getObject方法

• ClassPathMapperScanner：definition.setAutowireMode（2）修改了自动注入状态，所以MapperFactoryBean中setSqlSessionFactory会自动注入进去