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"/>
<!-- 上傳後的目錄名 -->
<!--<property name="uploadTempDir" value="/upload"/>-->
<!-- 最大文件大小，-1爲無限止(-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爲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中利用註解@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以爲，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，然後重寫其中的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);
}
}
controller
@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
轉自：https://www.cnblogs.com/userrain/p/5433233.html
