Mybatis入门编写

Mybatis入门编写

mybatis-config.xml的编写

Mybatis工具类的编写,用于获取SqlSession对象

  private static SqlSessionFactory sqlSessionFactory=null;
    static {
        try {
            //获取SqlSessionFactory对象
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }

Mapper.xml

    
        select * from ljqdb.user
    

测试类的编写

 SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List all = mapper.findAll();
        for (User user : all){
            System.out.println(user);
        }
        sqlSession.close();

由于maven约定大于配置,解决配置文件无法到处或者生效的问题

        
            
                src/main/resources
                
                    ***.xml
                
                true
            
            
                src/main/java
                
                    ***.xml
                
                true