规则
Mapper.xml文件中的namespace与mapper接口的全限定名相同
Mapper接口方法名和Mapper.xml中定义的每个statement的id相同
Mapper接口方法输入参数类型和mapper.xml中定义每个sql的parameterType类型相同
Mapper接口方法的输出参数类型和mapper.xml中定义的每个sql的resultType的类型相同
简单：Mapper接口的全限定类名，方法名，参数类型，返回值类型和mapper.xml中 , 对应上即可不需写dao实现 代理需要的api sqlSession.getMapper(Class class) 参数： Class ：mapper的class 返回值类型：T 返回值意义：获取代理实现后的Mapper 作用：获取代理实现后的Mapper InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapperConfig.xml"); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream); SqlSession sqlSession = sqlSessionFactory.openSession(true); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.findUserById(2); System.out.println(user); sqlSession.close();
对应上即可不需写dao实现
代理需要的api
sqlSession.getMapper(Class class)
参数：
Class ：mapper的class
返回值类型：T
返回值意义：获取代理实现后的Mapper
作用：获取代理实现后的Mapper
InputStream resourceAsStream = Resources.getResourceAsStream("sqlMapperConfig.xml"); SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(resourceAsStream); SqlSession sqlSession = sqlSessionFactory.openSession(true); UserMapper mapper = sqlSession.getMapper(UserMapper.class); User user = mapper.findUserById(2); System.out.println(user); sqlSession.close();