Question

I’d like to limit the size of the file that can be uploaded to an application. To achieve this, I’d like to abort the upload process from the server side when the size of the file being uploaded exceeds a limit.

Is there a way to abort an upload process from the server side without waiting the HTTP request to finish?

Answer 1

You can do something like this (using the Commons library):

    public class UploadFileServiceImpl extends HttpServlet     {         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException         {             response.setContentType('text/plain');              try             {                 FileItem uploadItem = getFileItem(request);                 if (uploadItem == null)                 {                         // ERROR                 }                     // Add logic here             }             catch (Exception ex)             {                 response.getWriter().write('Error: file upload failure: ' + ex.getMessage());                        }         }          private FileItem getFileItem(HttpServletRequest request) throws FileUploadException         {             DiskFileItemFactory factory = new DiskFileItemFactory();                       // Add here your own limit                       factory.setSizeThreshold(DiskFileItemFactory.DEFAULT_SIZE_THRESHOLD);           ServletFileUpload upload = new ServletFileUpload(factory);               // Add here your own limit              upload.setSizeMax(DiskFileItemFactory.DEFAULT_SIZE_THRESHOLD);               List<?> items = upload.parseRequest(request);             Iterator<?> it = items.iterator();             while (it.hasNext())             {                 FileItem item = (FileItem) it.next();                         // Search here for file item                 if (!item.isFormField() &&                    // Check field name to get to file item  ...                  {                     return item;                 }             }              return null;         }     }