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file upload controller class for handle multipart file upload requestcom.controller.FileUploadControllerclass FileUploadController implements file upload functionality with progress trackinglog = logger.getLogger(FileUploadController.class)upload method implementation@Controller@RequestMapping("/upload.html")public ModelAndView upload(HttpServletRequest request, HttpServletResponse response) throws Exception {create session instancesession = request.getSession()modelAndView = new ModelAndView()check if request is multipartisMultipart = ServletFileUpload.isMultipartContent(request)if (!isMultipart) {    return modelAndView;}create disk file item factoryFileItemFactory factory = new DiskFileItemFactory();initialize file upload serviceuploadService = new ServletFileUpload(factory);set progress listeneruploadService.setProgressListener(new ProgressListener() {    // progress updating logic    public void update(long bytesRead, long contentLength, int items) {        ProcessInfo info = new ProcessInfo();        info.itemNum = items;        info.readSize = bytesRead;        info.totalSize = contentLength;        info.show = String.format("%d/%d byte", bytesRead, contentLength);        info.rate = (int)(Math.round((float)bytesRead / contentLength * 100));        session.setAttribute("processInfo", info);    }});parse requestitems = uploadService.parseRequest(request)process uploaded itemsforeach (item in items) {    if (item is form field) {        // handle common form fields    } else {        // handle file upload fields        String fileName = item.getName();        String contentType = item.getContentType();        File uploadedFile = new File(("c://" + fileName));        item.write(uploadedFile);    }}return modelAndView}process method for getting progress info@RequestMapping("/process.json", method=RequestMethod.GET)@ResponseBodypublic Object process(HttpServletRequest request, HttpServletResponse response) throws Exception {    return session.getAttribute("processInfo");}class ProcessInfo {    // properties and fields}