Encapsulating the business logic with a POJO façade - POJOs in Action: Developing Enterprise Applications with Lightweight Frameworks - page 266

:Presentation
Tier

:PlaceOrder
Facade

:Browser

selectRestaurant(restaurantId)

updateRestaurant(pendingOrderId, restaurantId)

PendingOrder+Restaurant+MenuItems

HTML page

Figure 7.5 Handling the request that selects a restaurant

This method takes as parameters the pendingOrderId , which is stored in the
HttpSession , and the restaurant ID from the HTTP request. It returns a PlaceOr-
derFacadeResult , which consists of a status code, and the PendingOrder , which con-
tains the delivery information and a reference to the selected restaurant and its
menu items:

public class PlaceOrderFacadeResult {

private int statusCode;
private PendingOrderDetail pendingOrder;

public PlaceOrderFacadeResult(
int statusCode,
PendingOrderDetail pendingOrder) {
this.statusCode = statusCode;
this.pendingOrder = pendingOrder;
}
…
The status code indicates the outcome of calling the method. A façade method
can often have several expected outcomes, and a status code is a good way to com-
municate the outcome along with the data to display to the caller. PendingOrder-
Detail , which we first saw in section 7.2.1, is a view interface that provides a read-
only view of pending orders and is implemented by the PendingOrder class.