一、概述SpringMVC 处理请求的过程
1. DispatchServlet
protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception 相关代码
// Determine handler adapter for the current request. HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());// Actually invoke the handler. mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
2. 什么是HandlerAdapter
在以前的文章中,已经说过RequestMappingHandlerAdapter是处理输入输出的关键点
HandlerAdapter的handle()会调用
RequestMappingHandlerAdapter的invokeHandlerMethod()
protected ModelAndView invokeHandlerMethod(HttpServletRequest request, HttpServletResponse response, HandlerMethod handlerMethod) throws Exception { ServletWebRequest webRequest = new ServletWebRequest(request, response); try { WebDataBinderFactory binderFactory = getDataBinderFactory(handlerMethod); ModelFactory modelFactory = getModelFactory(handlerMethod, binderFactory); //创建ServletInvocableHandlerMethod ServletInvocableHandlerMethod invocableMethod = createInvocableHandlerMethod(handlerMethod); invocableMethod.setHandlerMethodArgumentResolvers(this.argumentResolvers); invocableMethod.setHandlerMethodReturnValueHandlers(this.returnValueHandlers); invocableMethod.setDataBinderFactory(binderFactory); invocableMethod.setParameterNameDiscoverer(this.parameterNameDiscoverer); ModelAndViewContainer mavContainer = new ModelAndViewContainer(); mavContainer.addAllAttributes(RequestContextUtils.getInputFlashMap(request)); modelFactory.initModel(webRequest, mavContainer, invocableMethod); mavContainer.setIgnoreDefaultModelOnRedirect(this.ignoreDefaultModelOnRedirect); AsyncWebRequest asyncWebRequest = WebAsyncUtils.createAsyncWebRequest(request, response); asyncWebRequest.setTimeout(this.asyncRequestTimeout); WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request); asyncManager.setTaskExecutor(this.taskExecutor); asyncManager.setAsyncWebRequest(asyncWebRequest); asyncManager.registerCallableInterceptors(this.callableInterceptors); asyncManager.registerDeferredResultInterceptors(this.deferredResultInterceptors); if (asyncManager.hasConcurrentResult()) { Object result = asyncManager.getConcurrentResult(); mavContainer = (ModelAndViewContainer) asyncManager.getConcurrentResultContext()[0]; asyncManager.clearConcurrentResult(); if (logger.isDebugEnabled()) { logger.debug("Found concurrent result value [" + result + "]"); } invocableMethod = invocableMethod.wrapConcurrentResult(result); } //调用 invocableMethod.invokeAndHandle(webRequest, mavContainer); if (asyncManager.isConcurrentHandlingStarted()) { return null; } return getModelAndView(mavContainer, modelFactory, webRequest); } finally { webRequest.requestCompleted(); } }
3.
4. 疑问:这些HandlerMethond是什么时候载入系统的
系统实例化的时候执行registerHandlerMethod()方法