servlet 

Httpservlet -- java

FrameworkServlet

DispatcherServlet
--初始化九大组件
doDispatcher
--
mappedHandler = getHandler(processedRequest, false);
HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
if (!mappedHandler.applyPreHandle(processedRequest, response)) {
	return;
}
// Actually invoke the handler.
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
mappedHandler.applyPostHandle(processedRequest, response, mv);
processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);