Using an exposed domain model - POJOs in Action: Developing Enterprise Applications with Lightweight Frameworks - page 292

Figure 8.3 shows the presentation and business tier components that are
responsible for processing the submission of the form and displaying the list of
available restaurants. The presentation tier consists of the servlet filter, which
opens and closes the JDO PersistenceManager or Hibernate Session ; the Update-
DeliveryInfoServlet , which handles the form submission; and the restaurants.jsp
JSP page, which displays the list of available restaurants. The business logic con-
sists of the domain model classes that we developed in chapter 3.

Manages Hibernate
Session or JDO
PersistenceManager

Servlet Filter

<<servlet>>
UpdateDelivery
InfoServlet

<<jsp>>
restaurants.jsp

Presentation
Tier

service()

Spring TransactionInterceptor

PlaceOrder
Service

Business Logic

updateDeliveryInfo()

PendingOrder

updateDeliveryInfo()
getDeliveryInfo()
...

Restaurant

getName()
...

PendingOrderRepository

findOrCreatePendingOrder()

RestaurantRepository

findAvailableRestaurants()
isRestaurantAvailable()
...

Figure 8.3 An example of the presentation tier accessing the domain objects directly