SqlSessionFactoryBuilder 读取配置 mybatis-config.xml 

springboot里配置
mybatis.mapper-locations=classpath:mapper/*.xml

build SqlSessionFactory

SqlSessionFactory  openSession() 返回 SqlSession

SqlSession实例获取Mapper对象并运行 

SqlSession通过StatementID找到对应的MappedStatement对象

通过Executor 将MappedStatement对象进行解析，sql参数转化、动态sql拼接，生成jdbc Statement对象

MappedStatement 结果映射 

SqlSessionFactory
SqlSession 
Executor
StatementHandler
ParameterHandler
ResultHandler
TypeHandler

执行器 Executor (update, query, flushStatements, commit, rollback, getTransaction, close, isClosed)
参数处理器 ParameterHandler (getParameterObject, setParameters)
结果处理器 ResultSetHandler (handleResultSets, handleOutputParameters)
sql查询更新处理器 StatementHandler (prepare, parameterize, batch, update, query)


StatementHandler 使用ParameterHandler与ResultHandler分别进行参数绑定与结果处理
ParameterHandler与ResultHandler都使用TypeHandler进行映射

SqlSessionFactory --> SqlSession --> Executor  --> 
StatementHandler --> (ParameterHandler ResultHandler) --> TypeHandler



// 读取mybatis-config.xml文件
InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
// 创建SqlSessionFactory 
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
// 创建Session实例
SqlSession session = sqlSessionFactory.openSession();

// 数据库操作方法一 
Person person = session.selectOne("com.dyyx.mapper.PersonMapper.selectPersonById", 1);
// 数据库操作方法二：获取mapper接口代理对象
PersonMapper personMapper = session.getMapper(PersonMapper.class);
Person person2 = personMapper.selectPersonById(1);
  
// 提交事务
session.commit();
// 关闭Session
session.close();





原理图
https://gitee.com/dyyx/work2024/tree/master/docs/mybatis/images/

mybatis001.webp   mybatis002.webp  mybatis003.webp