## Using FileUpload 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:
    DiskFileItemFactory factory = DiskFileItemFactory.builder()
      // Set upload parameters
      .setBufferSize(MAX_MEMORY_SIZE)
      .setPath(Paths.get(TEMP_DIR))
      .get();

    // Create a new file upload handler
    JakartaServletDiskFileUpload upload = new JakartaServletDiskFileUpload(factory);
    upload.setSizeMax(MAX_UPLOAD_SIZE);

    // Parse the request
    List<DiskFileItem> items = upload.parseRequest(request);

    // Process the uploaded fields
    for (DiskFileItem item :items) {
        if (item.isFormField()) {
            processTextParameter(request, item);
        } else {
            processFileParameter(request, item);
        }
    }