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

 
      org.springframework
      spring-jdbc
      5.2.5.RELEASE
    
    
      org.mybatis
      mybatis-spring
      2.0.4
    

• 编写Mapper和Mapper.xml

• 配置SqlSessionFactory和MapperScannerConfigurer

•  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