
310 VisualAge for Java Version 3: Persistence Builder with GUIs, Servlets, and JSPs
Application Controller
The application controller, or controller for short, works as a manager
between the different application layers. Its task is to delegate the work and
to control what is happening inside the application. We can describe the flow
of information in the controller thus:
❑ Whenever an event occurs, for example, a user clicks on a button, the user
interface layer invokes a method in the controller, and this method
invokes one or multiple methods in the business object layer.
❑ The controller checks the result of methods in the business object layer ...