How to trap SizeLimitExceededException with apache FileUpload?

I have an application that allows people to submit multiple files via the web. I'm using a jQuery multiple file upload
plugin on the front-end and I'm using Apache's FileUpload on the backend in my servlet.

I'm running into a problem where if the user tries to upload a file that exceeds the maximum size, I get an exception
and I can't seem to trap it. That means I can't display a meaningful error back to the user.

I've done some Google searches and found some code that looks like it may work, but it's way too complex for me
to even begin understanding and most of it seems to involve either Struts, myFaces or Spring, none of which I'm
currently using.

Any ideas on how I can gracefully notify the user that the file is too large to upload?

This is (part of) the stack trace I get:

13:50:57,829 ERROR [STDERR] org.apache.commons.fileupload.FileUploadBase$SizeLimitExceededException: the request was rejected
                            because its size (7267399) exceeds the configured maximum (5000000)
13:50:57,829 ERROR [STDERR] 	at org.apache.commons.fileupload.FileUploadBase$FileItemIteratorImpl.<init>(FileUploadBase.java:914)
13:50:57,829 ERROR [STDERR] 	at org.apache.commons.fileupload.FileUploadBase.getItemIterator(FileUploadBase.java:331)
13:50:57,829 ERROR [STDERR] 	at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:349)
13:50:57,829 ERROR [STDERR] 	at org.apache.commons.fileupload.servlet.ServletFileUpload.parseRequest(ServletFileUpload.java:126)
13:50:57,829 ERROR [STDERR] 	at com.project.controller.Application.parseRequest(Application.java:258)
13:50:57,829 ERROR [STDERR] 	at com.project.controller.Application.service(Application.java:46)
13:50:57,829 ERROR [STDERR] 	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
13:50:57,829 ERROR [STDERR] 	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

The error occurs when I try to do this:

I try to catch it as follows

but it isn't caught.

Here's more complete code:

public class Application extends HttpServlet {
	//stuff cut out here
		try {
			List<FileItem> fileItems = parseRequest(request, response);
			List<String> validationErrors = new ArrayList<String>();			
			String fieldLabel = "";
			Inquiry inquiry = new Inquiry();
			String validationMsg = "";
			
			Iterator<FileItem> iter = fileItems.iterator();
			while (iter.hasNext()) {
				FileItem item = (FileItem) iter.next();
				if (item.isFormField()) {
					//processFormField(item);
					//do stuff
				} else {  //processUploadedFile(item);
					long fileSize = item.getSize();
					String contentType = item.getContentType();
					
					If (item.getName().length() != 0) {
						File uploadedFile = new File("c:\\temp\\" + item.getName());
						item.write(uploadedFile);
						attachmentCt++;
						attachmentList.add(item.getName());
					} 					
				}			
			}
		} catch (Exception e) {
			String errMsg = "An exception has occurred while processing a vendor inquiry.";
			logger.error(errMsg, e);
			e.printStackTrace();			
			session.setAttribute("errorMessage", errMsg);
			response.sendRedirect(request.getContextPath() + "/" + "inquiry.jsp");
			return;
		}
	}

@SuppressWarnings("unchecked")  //this is needed to suppress the error:
	//Type safety: The expression of type List needs unchecked conversion to conform to List<FileItem>
	//at line fileItems = upload.parseRequest(request);
	//see http://mannionjava.blogspot.com/2006/09/expression-of-type-x-needs-unchecked.html
	private List<FileItem> parseRequest(final HttpServletRequest request, final HttpServletResponse response) {
		HttpSession session = request.getSession(true);
		List<FileItem> fileItems = null;
		try {
			//Create a factory for disk-based file items
			DiskFileItemFactory factory = new DiskFileItemFactory();
			//Set factory constraints
			//maximum size that will be stored in memory
			final int maxMemSize = Integer.parseInt(properties.getProperty("file.maxsize.mem"));
			factory.setSizeThreshold(maxMemSize);
			//the location for saving data that is larger than getSizeThreshold()
			factory.setRepository(new File(fileuploadLocation));

//Create a new file upload handler
			ServletFileUpload upload = new ServletFileUpload(factory);
			//set overall request size constraint 
			//it max size before a FileUploadException will be thrown
			final long maxSize = Long.parseLong(properties.getProperty("file.maxsize.before.exception"));			
			upload.setSizeMax(maxSize);
			//Parse the request			
			fileItems = upload.parseRequest(request);			
			return fileItems;
		} catch (FileUploadBase.SizeLimitExceededException se) {
			String errMsg = "File exceeds size limit.";
			logger.error(errMsg, se);
			se.printStackTrace();			
			session.setAttribute("errorMessage", errMsg);
			return fileItems; 
		} catch (FileUploadException fe) {
			String errMsg = "A file upload exception has occurred while parsing a vendor inquiry.";
			logger.error(errMsg, fe);
			fe.printStackTrace();			
			session.setAttribute("errorMessage", errMsg);
			return fileItems;
		} catch (IOException ioe) {
			String errMsg = "An IO exception has occurred while reading the properties file.";
			logger.error(errMsg, ioe);
			ioe.printStackTrace();			
			session.setAttribute("errorMessage", errMsg);
			return fileItems; 
		}

}

Since you have not provided your complete code (which is probably a good thing), it is a little hard to determine what the problem is.

Could you please indicate which of those lines you provided is line 46 in your real code? And what is the code at line 258 in your real code?

Moving to appropriate forum.

This is line 46:

List<FileItem> fileItems = parseRequest(request, response);
(line 4 above)

And this is line 258:
fileItems = upload.parseRequest(request);
(line 62 above)

So, when it does the parse, it generates the exception.

Thanks!

Are you sure it is not catching it? Did you try it in the debugger or carefully examine the log output?

What exactly happens when the size limit is exceeded? It looks like you are just returning like normal but would then get a null pointer because your fileItems would be null.

I plugged your catch blocks into my working file upload's try and it caught just fine on the first catch:

I tried it again, and made a few changes and I got it to the point where it does catch it, but not in the way I expected. Usually I can catch the error and handle it somehow and return gracefully to the user. In this case, it catches the exception, but there doesn't seem to be any way to give the user back their session variables, or recover their data. The best I can do it present the user with the error and the web form that is missing all the text they entered. I'll have to work at it some more I guess. Maybe if I move the upload fields to a separate form and submit them separately from the rest of the form I can work with that somehow.

Hi,

I have the same problem with you, that means if I attach big file size, then all the data filled on the form is lost.

If you have resolved your pb, could you share it with me, please? Thanks.

Regards,
Hoc NGUYEN THANH (thanh.hoc@gmail.com)

Hi nguyen Thanh Hoc and welcome to Javaranch!

It might be a good idea to start a new thread with the exact problem you have (with your code)

Did anybody else find a solution to solve this problem?

any additional clue?