Sometimes, enterprise applications use a stand-alone client application for handling tasks such as system or application administration. For example, the Duke's Bank application uses an application client to administer customers and accounts. This capability is useful in the event that the site becomes inaccessible for any reason or if a customer prefers to communicate things such as changes to account information by phone.
The application client shown in Figure 373 handles basic customer and account administration for the banking application through a Swing user interface. The bank administrator can perform any of the following functions on the respective tabs.
Figure 373. Application Client
Customer Info tab:
Error and informational messages appear in the bottom under Messages.
The Classes and Their Relationships
The source code for the application client is in the <INSTALL>/javaeetutorial5/examples/dukesbank/dukesbank-appclient/src/java/com/sun/tutorial/javaee/dukesbank/client/ directory. The application client is consists of a single class: BankAdmin.
The BankAdmin class, which creates the user interface, is a Swing class that provides action methods that are called when certain events occur in the application, and methods that call the controller session beans. It was created using the NetBeans 5.5 Swing editor, Matisse.
Although BankAdmin was written using NetBeans 5.5, you do not need to have NetBeans installed in order to run the application. If you want to alter the user interface, however, you do need to use NetBeans.
The BankAdmin constructor creates the initial user interface, which consists of a menu bar, two tabs, and a message pane, by calling the initComponents method. The menu bar contains the standard File and Edit menus, the left tab is for viewing and updating customer information, the right tab is for viewing and updating account information, and the message pane contains a message area.
The initComponents method is automatically generated by NetBeans. It creates all the user interface elements visible in BankAdmin.
The BankAdmin class provides methods that other objects call when they need to update the user interface. These methods are as follows:
The following methods interact with the controller session beans to create and update customer and account information:
The <UI Element>MouseReleased methods are linked to the GUI controls in BankAdmin. They call the previous methods to enable/disable the GUI fields, and create/update accounts and customers.