Mybatis 源码解析

Mybatis自动装配
spring.factories
MybatisAutoConfiguration
AutoConfiguredMapperScannerRegistrar----->ImportBeanDefinitionRegistrar
    registerBeanDefinitions(
        ClassPathMapperScanner.doScan(StringUtils.toStringArray(packages))   扫描注解Mapper.class
            ClassPathBeanDefinitionScanner.doScan
                this.findCandidateComponents(basePackage)
    


实例化SqlSessionFactory时，解析XML
@Bean
SqlSessionFactory
    new SqlSessionFactoryBean()
    factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapping/*.xml"))        加载xml
    factoryBean.getObject()
        this.afterPropertiesSet()
            this.buildSqlSessionFactory()
                循环并解析所有xml
                new XMLMapperBuilder
                    new XPathParser
                        this.createDocument(new InputSource(inputStream));
                            DocumentBuilderFactory.newInstance()
                            factory.newDocumentBuilder()
                            builder.parse(inputSource)            解析成Document
                xmlMapperBuilder.parse()
                    this.configurationElement(this.parser.evalNode("/mapper"));
                        this.builderAssistant.setCurrentNamespace(namespace);
                        this.cacheRefElement(context.evalNode("cache-ref"));
                        this.cacheElement(context.evalNode("cache"));
                        this.parameterMapElement(context.evalNodes("/mapper/parameterMap"));
                        this.resultMapElements(context.evalNodes("/mapper/resultMap"));
                        this.sqlElement(context.evalNodes("/mapper/sql"));
                        this.buildStatementFromContext(context.evalNodes("select|insert|update|delete"));        解析成MappedStatement
                            new XMLStatementBuilder
                            statementParser.parseStatementNode()
                                langDriver.createSqlSource        创建sql
                                    XMLScriptBuilder.parseScriptNode()
                                        new DynamicSqlSource        动态sql 包含if，while，${xx}等
                                        new RawSqlSource            非动态sql
                                            SqlSourceBuilder.parse()
                                                GenericTokenParser.parse()        替换#{xxx} 为问号？
                                                    new StaticSqlSource            封装成静态SqlSource返回
                                this.builderAssistant.addMappedStatement
                                    new org.apache.ibatis.mapping.MappedStatement.Builder
                                    this.getStatementParameterMap
                                    statementBuilder.parameterMap(statementParameterMap)
                                    statementBuilder.build()        MappedStatement
                                    this.configuration.addMappedStatement(statement)        添加到configuration的mappedStatements
                    this.bindMapperForNamespace()
                        boundType = Resources.classForName(namespace)        加载Mapper class
                        this.configuration.addMapper(boundType)                注册Mapper
                            this.mapperRegistry.addMapper(type)                MapperRegistry
                                this.knownMappers.put(type, new MapperProxyFactory(type))                添加addMapper，调用的时候getMapper
                                MapperAnnotationBuilder parser = new MapperAnnotationBuilder(this.config, type)        注解方法解释器
                                parser.parse()
                                    this.type.getMethods()
                                    循环解析methodd的注解  this.parseStatement(method)    
                循环结束
                this.sqlSessionFactoryBuilder.build(targetConfiguration)
                    new DefaultSqlSessionFactory(config)-----方法openSession---事务，Executor new DefaultSqlSession
                    

@Autowired
private UserMapper userMapper;
实例化Controller
    实例化Service
        实例化Mapper         MapperFactoryBean
            MapperFactoryBean.getObject()
                this.getSqlSession().getMapper(this.mapperInterface)
                    DefaultSqlSession.configuration.getMapper(type, this);
                        MapperRegistry.mapperRegistry.getMapper(type, sqlSession);
                            MapperProxyFactory.newInstance(sqlSession);
                                this.newInstance(new MapperProxy(sqlSession, this.mapperInterface, this.methodCache));
                                    Proxy.newProxyInstance(this.mapperInterface.getClassLoader(), new Class[]{this.mapperInterface}, mapperProxy);                    



调用Mapper方法                    
User user = userMapper.selectOne("dd")
    MapperProxy.invoke(Object proxy, Method method, Object[] args)                            implements InvocationHandle
        MapperMethod.execute(this.sqlSession, args)
            sqlSession.selectOne(this.command.getName(), param)
                this.sqlSessionProxy.selectOne(statement, parameter)
                    SqlSessionInterceptor.invoke(Object proxy, Method method, Object[] args)
                        SqlSession sqlSession = SqlSessionUtils.getSqlSession(xxx
                        Object result = method.invoke(sqlSession, args)     调用反射方法
                        sqlSession.commit(true)         看情况执行
                        SqlSessionUtils.closeSqlSession(xxx
                            反射方法
                            DefaultSqlSession.selectOne
                                this.executor.query(ms, this.wrapCollection(parameter), rowBounds, Executor.NO_RESULT_HANDLER)
                                    CachingExecutor.query(
                                        this.delegate.query(ms, parameterObject, rowBounds, resultHandler, key, boundSql)
                                            BaseExecutor.query(
                                                this.queryFromDatabase(
                                                    this.doQuery(
                                                        this.prepareStatement(
                                                            this.getConnection(statementLog)
                                                                this.transaction.getConnection()
                                                                    SpringManagedTransaction.openConnection()
                                                                        DataSourceUtils.getConnection(this.dataSource)
                                                                            doGetConnection(dataSource)
                                                                                fetchConnection(dataSource)
                                                                                    dataSource.getConnection()
                                                                                        new HikariPool(this)                    创建线程池
                                                                                            dataSource = new DriverDataSource(jdbcUrl, driverClassName, dataSourceProperties, username, password)
                                                            StatementHandler.prepare(connection, this.transaction.getTimeout())
                                                                StatementHandler.prepare(connection, transactionTimeout)
                                                                    this.instantiateStatement(connection)
                                                                        connection.prepareStatement(sql)
                                                            StatementHandler.parameterize(stmt)
                                                        PreparedStatementHandler.query(statement, resultHandler)
                                                            ps.execute()
                                                            this.resultSetHandler.handleResultSets(ps)   DefaultResultSetHandler
                                                                ResultSetWrapper rsw = this.getFirstResultSet(stmt)                获取字段属性映射关系
                                                                循环记录数
                                                                    this.handleResultSet(rsw, resultMap, multipleResults, (ResultMapping)null)
                                                                        this.handleRowValues(rsw, resultMap, this.resultHandler, this.rowBounds, (ResultMapping)null)        处理字段值
                                                                            this.handleRowValuesForSimpleResultMap(rsw, resultMap, resultHandler, rowBounds, parentMapping);    分为简单和嵌套
                                                                                this.getRowValue(rsw, discriminatedResultMap);
                                                                                    rowValue = this.createResultObject(rsw, resultMap, lazyLoader, columnPrefix)
                                                                                        各种方式创建
                                                                                    this.applyAutomaticMappings(rsw, resultMap, metaObject, (String)null) || foundValues        应用自动映射
                                                                                        this.createAutomaticMappings(rsw, resultMap, metaObject, columnPrefix);
                                                                                        mapping.typeHandler.getResult(rsw.getResultSet(), mapping.column);            调用类型处理器
                                                                                    this.applyPropertyMappings
                                                                                    this.applyNestedResultMappings
                                                                循环结束
                                                this.localCache.putObject(key, list)        缓存