if (!isFirstCarDateValid(parkingRequestFactoryCreator, request)) { RenderUtils.invalidateViewState();
if (!isFirstCarDataValid(parkingRequestFactoryCreator, request)) { RenderUtils.invalidateViewState();
    public ActionForward createParkingRequest(ActionMapping mapping, ActionForm actionForm,            HttpServletRequest request, HttpServletResponse response) throws Exception {        ParkingRequestFactoryCreator parkingRequestFactoryCreator = (ParkingRequestFactoryCreator) getFactoryObject();        request.setAttribute("parkingRequestFactoryCreator", parkingRequestFactoryCreator);        DynaActionForm parkingForm = (DynaActionForm) actionForm;        if (!isFirstCarDateValid(parkingRequestFactoryCreator, request)) {            RenderUtils.invalidateViewState();            return mapping.getInputForward();        }        ajustParkingRequest(parkingForm, parkingRequestFactoryCreator);        if (!areFileNamesValid(parkingRequestFactoryCreator, request)) {            RenderUtils.invalidateViewState();            return mapping.getInputForward();        }        executeService(request, "ExecuteFactoryMethod", new Object[] { parkingRequestFactoryCreator });        return prepareParking(mapping, actionForm, request, response);    }