Some people using Oracle need to know about technologies such as BEA WebLogic Server, WebLogic Portal, WebLogic Integration, WebLogic Workshop, and Liquid Data for WebLogic. Because there are no use case realizations to be detailed in the Logical View, the Logical Keep in mind that an application should be constructed so that any component only accesses components within its layer or any lower layer. Exceptions to this constraint should be very rare and well justified. Components are allowed to access lower layers that are not adjacent.



For example, a component in the Presentation and Interface layer may access a component in the Business Logic layer directly without using any component in the Business Process layer. However, it is important to remember that the layers exist for a reason and should not be bypassed arbitrarily.

It is helpful to know that the presentation and Interface layer is responsible for providing the interface to the application. This might be in the form of a browser interface for a web or portal application or a programmatic interface for a rich client or another system..

Keep in mind that a web logic service, a component of the Presentation layer, can receive a callback from a custom Java control, a component of the lower Business Logic layer. However, callbacks are a response channel set up by a higher level component for a lower layer component it invokes. Also, the higher layer invites callbacks and explicitly provides handlers for the callbacks it receives. Consequently, callbacks adhere to the inter-layer communication rules and, in fact, provide a simple mechanism for asynchronous communication between mechanisms.

Also good to know if you are interested in WebLogic is that fact that components of the Business Logic layers can be exposed in the Presentation and Integration layer through programmatic interfaces. Exposing a programmatic interface allows the application to participate as a supplier in a Service-Oriented Architecture. The Data Access and Integration layer allows this application to consume services provided by other systems in an SOA. Therefore, this application architecture facilitates a true SOA where business logic and business processes can be shared between applications, thereby facilitating composite application construction.

Also, web interface provides the simplest user interface into the application. The web browser client application is the platform that hosts the user interface for all web applications. Content displayed in the browser is mostly static, except for client-side processing driven by JavaScript. Client-side processing is usually leveraged to do light initial data validation or to visually enhance the user interface.

Also, it is good to know that a portal interface gives users a single point of access to applications and information in a unified interface. Also, a portal interface can provide content and applications to multiple audiences with reusable portal resources. A portal interface also allows large amounts of data to be organized and accessed easily. A programmatic interface allows other applications to access data, business processes, and business WebLogic.