protected void doService(HttpServletRequest request, HttpServletResponse response) throws Exception {

    		// 保存请求中的所有属性,在最后DipatcherServlet处理完后,将请求中的属性全部还原回去
    		Map<String, Object> attributesSnapshot = null;
    		if (WebUtils.isIncludeRequest(request)) {
    			attributesSnapshot = new HashMap<String, Object>();
    			Enumeration<?> attrNames = request.getAttributeNames();
    			while (attrNames.hasMoreElements()) {
    				String attrName = (String) attrNames.nextElement();
    				if (this.cleanupAfterInclude || attrName.startsWith("org.springframework.web.servlet")) {
    					attributesSnapshot.put(attrName, request.getAttribute(attrName));
    				}
    			}
    		}

    		// 在请求中放入, 上下文, 本地化,主题,等处理器
    		request.setAttribute(WEB_APPLICATION_CONTEXT_ATTRIBUTE, getWebApplicationContext());
    		request.setAttribute(LOCALE_RESOLVER_ATTRIBUTE, this.localeResolver);
    		request.setAttribute(THEME_RESOLVER_ATTRIBUTE, this.themeResolver);
    		request.setAttribute(THEME_SOURCE_ATTRIBUTE, getThemeSource());
    		FlashMap inputFlashMap = this.flashMapManager.retrieveAndUpdate(request, response);
    		if (inputFlashMap != null) {
    			request.setAttribute(INPUT_FLASH_MAP_ATTRIBUTE, Collections.unmodifiableMap(inputFlashMap));
    		}
    		request.setAttribute(OUTPUT_FLASH_MAP_ATTRIBUTE, new FlashMap());
    		request.setAttribute(FLASH_MAP_MANAGER_ATTRIBUTE, this.flashMapManager);

        // 请求派发,将请求交由对应的控制器处理(包含拦截器调用)
    		try {
    			doDispatch(request, response);
    		}
    		finally {
    			if (!WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {
    				// 将最开始保存的请求属性全部还原回去
    				if (attributesSnapshot != null) {
    					restoreAttributesAfterInclude(request, attributesSnapshot);
    				}
    			}
    		}
    	}

    try {
    				processedRequest = checkMultipart(request);
    				multipartRequestParsed = (processedRequest != request);

    				// 获取当前的请求对应的处理器(包括拦截器和真实处理请求的控制器)
    				mappedHandler = getHandler(processedRequest);
    				if (mappedHandler == null || mappedHandler.getHandler() == null) {
    					noHandlerFound(processedRequest, response);
    					return;
    				}

    				// 获取当前请求对于的处理器适配器
    				HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());

    				// 这里是在处理支持 last-modified 请求头的情况
    				String method = request.getMethod();
    				boolean isGet = "GET".equals(method);
    				if (isGet || "HEAD".equals(method)) {
    					long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
    					if (logger.isDebugEnabled()) {
    						logger.debug("Last-Modified value for [" + getRequestUri(request) + "] is: " + lastModified);
    					}
    					if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {
    						return;
    					}
    				}

            // 执行 所有拦截器的preHandle()方法,若有拦截器的preHandle未通过,则会执行所有已经执行过的拦截器的 afterCompletion() 方法
            // 拦截器未通过,则直接结束请求.
    				if (!mappedHandler.applyPreHandle(processedRequest, response)) {
    					return;
    				}

    				// 真正的控制器处理请求
    				mv = ha.handle(processedRequest, response, mappedHandler.getHandler());

            // 这里是处理servlet3.0支持的异步处理的请求
    				if (asyncManager.isConcurrentHandlingStarted()) {
    					return;
    				}

            // 设置默认视图名称
    				applyDefaultViewName(processedRequest, mv);

            // 调用所有拦截器的 postHandle() 方法(与preHandle()执行顺序的相反)
    				mappedHandler.applyPostHandle(processedRequest, response, mv);
    			}
    			catch (Exception ex) {
    				dispatchException = ex;
    			}

          // 处理派发请求的结果,做视图渲染,异常处理,并且会调用所有拦截器的 afterCompletion() 方法
    			processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);

  @Override
  	protected boolean isHandler(Class<?> beanType) {
  		return ((AnnotationUtils.findAnnotation(beanType, Controller.class) != null) ||
  				(AnnotationUtils.findAnnotation(beanType, RequestMapping.class) != null));
  	}