FileUpload_servlet (only part)

FileUpload

// Validate file.
        Object fileObject = request.getAttribute("file");
        if (fileObject == null) {
            // No file uploaded.
            myForm.setError("file", "Please select file to upload.");
        }



private void processFileField(FileItem fileField, HttpServletRequest request) 
{
        if (fileField.getName().length() <= 0) 
{
            // No file uploaded.
            request.setAttribute(fileField.getFieldName(), null);
        } 

else if (maxFileSize > 0 && fileField.getSize() > maxFileSize) 
{
            // File size exceeds maximum file size.
            request.setAttribute(fileField.getFieldName(), new FileUploadException(
                "File size exceeds maximum file size of " + maxFileSize + " bytes."));
            // Immediately delete temporary file to free up memory and/or disk space.
            fileField.delete();
        } 

else {
            // File uploaded with good size.
            request.setAttribute(fileField.getFieldName(), fileField);
        }

    }

//---------------------------------
// Prepare the multipart request items.
        // I'd rather call the "FileItem" class "MultipartItem" instead or so. What a stupid name ;)
        List<FileItem> multipartItems = null;

        try {
            // Parse the multipart request items.
            multipartItems = new ServletFileUpload(new DiskFileItemFactory()).parseRequest(request);
            // Note: we could use ServletFileUpload#setFileSizeMax() here, but that would throw a
            // FileUploadException immediately without processing the other fields. So we're
            // checking the file size only if the items are already parsed. See processFileField().
        } catch (FileUploadException e) {
            throw new ServletException("Cannot parse multipart request: " + e.getMessage());
        }

        // Prepare the request parameter map.
        Map<String, String[]> parameterMap = new HashMap<String, String[]>();

        // Loop through multipart request items.
        for (FileItem multipartItem : multipartItems) {
            if (multipartItem.isFormField()) {
                // Process regular form field (input type="text|radio|checkbox|etc", select, etc).
                processFormField(multipartItem, parameterMap);
            } else {
                // Process form file field (input type="file").
                processFileField(multipartItem, request);
            }
        }