Asynchronous file upload in Spring

Here's what I'm doing. I want to upload multipart file via Ajax to my Spring web app. When the server receives the POST request, it creates a ticket number in the database. It then starts a thread that handles the actual file upload. The server then returns the ticket number.

I am using the CommonsMultipartResolver to handle the request and I have set the resolveLazily flag to true so that the Multipart isn't resolved right away.

So here's something along the lines of what I have

@Controller
public class myController{

    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    @ResponseStatus(value = HttpStatus.OK)
    @ResponseBody
    public String upload(MultipartHttpServletRequest request, String fileName){

        String ticket = dao.createUploadTicket(fileName);
        Runnable run = new Runnable(){

            @Override
            public void run(){

                dao.writeUpdate(ticket, "Getting data from request");
                final MultipartFile file = request.getFile("theFile");
                dao.writeUpdate(ticket, "Multipart file processed");
                try {
                   dao.writeUpdate(ticket, "Saving file to disk");
                   file.transferTo(new File("/myDirectory"));
                   dao.writeUpdate(ticket, "File saved to disk");
                }
                catch(Exception e){
                   dao.writeUpdate(ticket, "File upload failed with the exception " + e.toString());
                }
            }
        };
        Thread t = new Thread(run);
        t.start();
        return ticket;
    }
}

So the point here is that the ticket number can be used to get the progress updates. Say a large file is being uploaded. The client that made the file upload POST (say in this instance an Ajax request) can do it asynchronously and get back a ticket number. The client can the use that ticket number to determine the stage of the file upload and dis