Spring中向服務器上傳圖片需要進行配置bean CommonsMultipartResolver；具體配置如下：
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 默認編碼 (ISO-8859-1) --> <property name="defaultEncoding" value="UTF-8"/> <!-- 最大內存大小 (10240) --> <property name="maxInMemorySize" value="10240"/> <!-- 上傳后的目錄名 --> <!--<property name="uploadTempDir" value="/upload"/>--> <!-- 最大文件大小，-1為無限止(-1),最大上傳文件3M --> <property name="maxUploadSize" value="3000000"/> </bean>
上面的配置中可以看到設置的文件上傳的大小限制為3M；當上傳的文件的大小超過上限時，便會拋出MaxUploadSizeExceededException異常。
今天遇到的最大的問題便是：如何優雅的處理MaxUploadSizeExceededException異常？
MaxUploadSizeExceededException異常的特殊之處在於，當上傳文件的大小超過限制時，它的拋出並是在進入Controller之前，所以不能在controller中利用注解@ExceptionHandler（MaxUploadSizeExceededException.class）來定義該異常的處理方法；
經過網上的搜索，出了利用filter以為，還看到其它三種處理辦法：
1.在xml中配置SimpleMappingExceptionResolver，其中加入對MaxUploadSizeExceededException異常的處理，指定對應的錯誤頁面，具體如下：
<!-- 全局異常處理 -->
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> <property name="exceptionMappings"> <props> <!-- 處理超過大小時的異常 --> <!--遇到MaxUploadSizeExceededException異常時，自動跳轉到/WEB-INF/views/errors/upload.jsp頁面 --> <prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">errors/upload</prop> </props> </property> </bean>
2.將對應的controller實現HandlerExceptionResolver接口，然后重寫其中的resolveException方法，返回ModelAndView，用於對MaxUploadSizeExceededException進行處理，具體如下：
@Controller
public class FileUploadController implements HandlerExceptionResolver { /*** Trap Exceptions during the upload and show errors back in view form ***/ public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception exception) { Map<String, Object> model = new HashMap<String, Object>(); if (exception instanceof MaxUploadSizeExceededException) { model.put("errors", exception.getMessage()); } else { model.put("errors", "Unexpected error: " + exception.getMessage()); } model.put("uploadedFile", new UploadedFile()); return new ModelAndView("/upload", model); } }
3.繼承CommonsMultipartResolver類，重寫parseRequest方法，在其中對MaxUploadSizeExceededException異常信息進行處理，放入request中，在controller再進行相應ModelAndView的返回，具體如下：
public class DropOversizeFilesMultipartResolver extends CommonsMultipartResolver { @Override protected MultipartParsingResult parseRequest(final HttpServletRequest request) { String encoding = determineEncoding(request); FileUpload fileUpload = prepareFileUpload(encoding); List fileItems; try { fileItems = ((ServletFileUpload) fileUpload).parseRequest(request); } catch (FileUploadBase.SizeLimitExceededException ex) { request.setAttribute(EXCEPTION_KEY, ex); fileItems = Collections.EMPTY_LIST; } catch (FileUploadException ex) { throw new MultipartException("Could not parse multipart servlet request", ex); } return parseFileItems(fileItems, encoding); } }
@InitBinder("fileForm")
protected void initBinderDesignForm(WebDataBinder binder) { binder.setValidator(new FileFormValidator()); } @RequestMapping(value = "/my/mapping", method = RequestMethod.POST) public ModelAndView acceptFile(HttpServletRequest request, Model model, FormData formData, BindingResult result) { Object exception = request.getAttribute(DropOversizeFilesMultipartResolver.EXCEPTION_KEY); if (exception != null && FileUploadBase.SizeLimitExceededException.class.equals(exception.getClass())) { result.rejectValue("file", "<your.message.key>"); LOGGER.error(exception); }
以上三種方法都能夠類似實現返回一個ModelAndView來實現對MaxUploadSizeExceededException進行處理；
http://stackoverflow.com/questions/2689989/how-to-handle-maxuploadsizeexceededexception
http://stackoverflow.com/questions/4029583/using-spring-3-exceptionhandler-with-commons-fileupload-and-sizelimitexceededex