Your application should detect whether or not FileUpload should be invoked, based on the HTTP method and the content type of the request.
Assuming that you have decided that FileUpload should be invoked, you might write the following code to handle a file upload request:
// Create a new file upload handler DiskFileUpload upload = new DiskFileUpload(); // Set upload parameters upload.setSizeMax(MAX_UPLOAD_SIZE); upload.setSizeThreshold(MAX_MEMORY_SIZE); upload.setRepositoryPath(TEMP_DIR); // Parse the request List items = upload.parseRequest(request); // Process the uploaded fields Iterator iter = items.iterator(); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (item.isFormField()) { processTextParameter(request, item); } else { processFileParameter(request, item); } }