MyBatis3.5.4源码之旅八之insert案例分析二

然后我们看invoke(proxy, method, args, sqlSession);执行就是我们刚才设置进去的MapperMethod的执行方法&＃xff1a;

MapperMethod的execute

然后进行命令的类型选择&＃xff0c;当然我们是Insert&＃xff1a;

然后获取传入的参数&＃xff1a;

DefaultSqlSession的insert

调用sqlSession.insert(command.getName(), param)进行插入内部居然调用的是update&＃xff1a;

DefaultSqlSession的update

&＃64;Overridepublic int update(String statement, Object parameter) {try {dirty &＃61; true;MappedStatement ms &＃61; configuration.getMappedStatement(statement);return executor.update(ms, wrapCollection(parameter));} catch (Exception e) {throw ExceptionFactory.wrapException("Error updating database. Cause: " &＃43; e, e);} finally {ErrorContext.instance().reset();}}


然后设置数据为脏数据&＃xff0c;从配置对象configuration中获取MappedStatement&＃xff0c;调用CachingExecutor执行器的update方法&＃xff0c;之前还会对参数进行包装。

CachingExecutor的update

&＃64;Overridepublic int update(MappedStatement ms, Object parameterObject) throws SQLException {flushCacheIfRequired(ms);return delegate.update(ms, parameterObject);}


先进行缓存的清除&＃xff1a;

private void flushCacheIfRequired(MappedStatement ms) {Cache cache &＃61; ms.getCache();if (cache !&＃61; null && ms.isFlushCacheRequired()) {tcm.clear(cache);}}


SimpleExecutor的update

然后调用委托执行器SimpleExecutor的update&＃xff0c;实则是调用了其父类BaseExecutor的update&＃xff1a;

&＃64;Overridepublic int update(MappedStatement ms, Object parameter) throws SQLException {ErrorContext.instance().resource(ms.getResource()).activity("executing an update").object(ms.getId());if (closed) {throw new ExecutorException("Executor was closed.");}clearLocalCache();return doUpdate(ms, parameter);}


SimpleExecutor的doUpdate

会先清除本地缓存clearLocalCache&＃xff0c;也就是我们说的一级缓存。然后进行doUpdate查询&＃xff1a;

&＃64;Overridepublic int doUpdate(MappedStatement ms, Object parameter) throws SQLException {Statement stmt &＃61; null;try {Configuration configuration &＃61; ms.getConfiguration();StatementHandler handler &＃61; configuration.newStatementHandler(this, ms, parameter, RowBounds.DEFAULT, null, null);stmt &＃61; prepareStatement(handler, ms.getStatementLog());return handler.update(stmt);} finally {closeStatement(stmt);}}


Configuration的newStatementHandler

可以看到需要生成一个StatementHandler&＃xff0c;内部做了些工作&＃xff0c;重新包装了下&＃xff0c;然后放进了拦截链&＃xff1a;

其实内部的处理器是PreparedStatementHandler&＃xff1a;

BaseStatementHandler的构造方法

最后调用到了BaseStatementHandler的构造函数&＃xff0c;里面会进行sql的封装&＃xff0c;会创建参数和结果集处理器&＃xff1a;

MappedStatement的getBoundSql

内部封了BoundSql返回。

好了&＃xff0c;今天就到这里了&＃xff0c;希望对学习理解有帮助&＃xff0c;大神看见勿喷&＃xff0c;仅为自己的学习理解&＃xff0c;能力有限&＃xff0c;请多包涵。