private Bill warmupRestaurant(String billId, Model uiModel) {
   Bill bill = billService.findById(Long.valueOf(billId));
   Collection<Restaurant> restaurants = restaurantService.findAll();
   uiModel.addAttribute("restaurants", restaurants);
   Restaurant restaurant =
       restaurantService.fetchWarmedUp(bill.getDiningTable().getRestaurant().getId());
   uiModel.addAttribute("restaurant", restaurant);
   return bill;
 }
 private Order warmupRestaurantByOrder(String orderId, Model uiModel) {
   Order order = orderService.findById(Long.valueOf(orderId));
   Collection<Restaurant> restaurants = restaurantService.findAll();
   uiModel.addAttribute("restaurants", restaurants);
   Restaurant restaurant =
       restaurantService.fetchWarmedUp(order.getBill().getDiningTable().getRestaurant().getId());
   uiModel.addAttribute("restaurant", restaurant);
   return order;
 }
 private void orderHasBeenServed(Order order) {
   try {
     orderService.orderServed(order);
   } catch (StateException e) {
     log.error(
         "Internal error has occurred! Order "
             + Long.valueOf(order.getId())
             + "has not been changed to served state!",
         e);
   }
 }
 private void billHasBeenPaid(Bill bill) {
   try {
     billService.billHasBeenPaid(bill);
   } catch (StateException e) {
     log.error(
         "Internal error has occurred! Order "
             + Long.valueOf(bill.getId())
             + "has not been changed to served state!",
         e);
   }
 }
  // this method serves kitchen subsystem and waiter subsystem requests,
  // which is quite confusing!
  // Reason is that the actual resource "orders/{orderId}" that is asked for,
  // is the same for kitchen subsystem and waiter subsystem,
  // meaning that the request URI is the same (according to REST).
  // You cannot have two methods with the same request URI mapping.
  // It is because the "event" request parameter (which is the distinguishing
  // parameter) is part of the HTTP body and can therefore not be
  // used for the request mapping.
  @RequestMapping(value = "/orders/{orderId}", method = RequestMethod.PUT)
  public String receiveEvent(
      @PathVariable("orderId") String orderId,
      @RequestParam String event,
      Model uiModel,
      Locale locale) {

    Order order = orderService.findById(Long.valueOf(orderId));
    Restaurant restaurant = warmupRestaurant(order, uiModel);

    switch (event) {
      case "planOrder":
        try {
          orderService.planOrder(order);
        } catch (StateException e) {
          logger.error(
              "Internal error has occurred! Order "
                  + Long.valueOf(orderId)
                  + "has not been changed to planned state!",
              e);

          // StateException triggers a rollback; consequently all Entities are invalidated by
          // Hibernate
          // So new warmup needed
          warmupRestaurant(order, uiModel);
          return "hartigehap/kitchen";
        }
        return "redirect:/restaurants/" + restaurant.getId() + "/kitchen";
        // break unreachable

      case "orderHasBeenPrepared":
        try {
          orderService.orderPrepared(order);
        } catch (StateException e) {
          logger.error(
              "Internal error has occurred! Order "
                  + Long.valueOf(orderId)
                  + "has not been changed to prepared state!",
              e);

          // StateException triggers a rollback; consequently all Entities are invalidated by
          // Hibernate
          // So new warmup needed
          warmupRestaurant(order, uiModel);
          return "hartigehap/kitchen";
        }
        return "redirect:/restaurants/" + restaurant.getId() + "/kitchen";
        // break unreachable

      case "orderHasBeenServed":
        try {
          orderService.orderServed(order);
        } catch (StateException e) {
          logger.error(
              "Internal error has occurred! Order "
                  + Long.valueOf(orderId)
                  + "has not been changed to served state!",
              e);

          // StateException triggers a rollback; consequently all Entities are invalidated by
          // Hibernate
          // So new warmup needed
          warmupRestaurant(order, uiModel);
          return "hartigehap/waiter";
        }
        return "redirect:/restaurants/" + restaurant.getId() + "/waiter";
        // break unreachable

      default:
        logger.error("Internal error: event " + event + " not recognized");
        return "redirect:/restaurants/" + restaurant.getId();
    }
  }