所在类：org.springframework.web.servlet.DispatcherServlet

    1.     protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
    2.         HttpServletRequest processedRequest = request;
    3.         HandlerExecutionChain mappedHandler = null;
    4.         boolean multipartRequestParsed = false;
    5.         WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request);
    7.         try {
    8.             try {
    9.                 ModelAndView mv = null;
    10.                 Object dispatchException = null;
    12.                 try {
    13.                     processedRequest = this.checkMultipart(request);
    14.                     multipartRequestParsed = processedRequest != request;
    15.                     mappedHandler = this.getHandler(processedRequest);
    16.                     if (mappedHandler == null) {
    17.                         this.noHandlerFound(processedRequest, response);
    18.                         return;
    19.                     }
    21.                     HandlerAdapter ha = this.getHandlerAdapter(mappedHandler.getHandler());
    22.                     String method = request.getMethod();
    23.                     boolean isGet = "GET".equals(method);
    24.                     if (isGet || "HEAD".equals(method)) {
    25.                         long lastModified = ha.getLastModified(request, mappedHandler.getHandler());
    26.                         if ((new ServletWebRequest(request, response)).checkNotModified(lastModified) && isGet) {
    27.                             return;
    28.                         }
    29.                     }
    31.                     if (!mappedHandler.applyPreHandle(processedRequest, response)) {
    32.                         return;
    33.                     }
    35.                     mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
    36.                     if (asyncManager.isConcurrentHandlingStarted()) {
    37.                         return;
    38.                     }
    40.                     this.applyDefaultViewName(processedRequest, mv);
    41.                     mappedHandler.applyPostHandle(processedRequest, response, mv);
    42.                 } catch (Exception var20) {
    43.                     dispatchException = var20;
    44.                 } catch (Throwable var21) {
    45.                     dispatchException = new NestedServletException("Handler dispatch failed", var21);
    46.                 }
    48.                 this.processDispatchResult(processedRequest, response, mappedHandler, mv, (Exception)dispatchException);
    49.             } catch (Exception var22) {
    50.                 this.triggerAfterCompletion(processedRequest, response, mappedHandler, var22);
    51.             } catch (Throwable var23) {
    52.                 this.triggerAfterCompletion(processedRequest, response, mappedHandler, new NestedServletException("Handler processing failed", var23));
    53.             }
    55.         } finally {
    56.             if (asyncManager.isConcurrentHandlingStarted()) {
    57.                 if (mappedHandler != null) {
    58.                     mappedHandler.applyAfterConcurrentHandlingStarted(processedRequest, response);
    59.                 }
    60.             } else if (multipartRequestParsed) {
    61.                 this.cleanupMultipart(processedRequest);
    62.             }
    64.         }
    65.     }