About Oracle ADF Business Domain Components, Data Model Components, and Organizational Components

Oracle ADF is a framework, meaning that much of its functionality is contained in a set of libraries. Specific applications add to or change the functionality of the library classes, creating specific business components.

What Oracle ADF Business Components Does

Oracle ADF Business Components are a portion of Oracle ADF that help you create business services for a J2EE application. That is, it governs interaction between the rest of the application (often called the client) and the data stored in the datasource, providing validation, specific services, and other business logic.

Note: Oracle ADF Business Components does not create a user interface (this is governed by the "view" portion of the client), nor does it determine other application logic such as control flow (this is governed by the "controller" portion of the client). It just provides a representation of and access to data and implements business logic.

The business components you create with the framework will handle the specific data needs of your application. You can do this in two ways:

You can create XML files to represent the needs of your particular application, and use only the base Oracle ADF Business Components classes (those included in the libraries). These classes will use the XML files to determine metadata and perform simple validation for your custom business components. For many applications, this is sufficient.
You can create both XML files and subclasses of the base Oracle ADF Business Components classes, and use your subclasses instead of the base Oracle ADF Business Components classes. This allows you to implement functionality (such as more complex validation and custom service methods for the rest of your application) not already provided by the framework, and to override many aspects of the framework's behavior.

Whichever method you use to create your individual business components, they will divide into three groups: business domain components, data model components, and organizational objects.

Business Domain Components

Business domain components are business components that represent features of the datasource. Business domain components are datasource-facing, which means that you do not need to design them with your application's specific data needs in mind. You should instead base them on the most logical representation of your data. If you already have a well-designed datasource, the structure of your business domain components should reflect the structure of the datasource. Because business domain components are datasource-facing, they are completely client agnostic. That is, they can be reused by any application which accesses the same database schema.

Oracle ADF Business Components has two kinds of business domain components:

Entity objects, which represent objects in the datasource (usually tables, views, and synonyms in a database)
Associations, which represent relationships between these objects (such as foreign key relationships)
Domains, which are special datatypes that represent Oracle Object Types or contain specialized business logic

For more information about entity objects and associations, see the related topics list.

Data Model Components

Data model components are business components that collect data and present it to the client model. Data model components are client-facing, which means that you should design them based on your client's specific data needs. Because data model components are tailored to a client's data needs, they are not as reusable as business domain components. However, data model components can be reused between applications that use the same data, even if those applications have very different ways of presenting the information (for example, the same data model components can be used by both a "rich" Java client and an HTML web application.

Oracle ADF Business Components has three kinds of data model components:

View objects, which collect data from the datasource (usually by using a SQL query)
View links, which represent relationships (such as master-detail relationships) between view object result sets
Application modules, which provide a single point of access to the view objects and view links.

For more information about view objects, view links, and application modules, see the related topics list

Organizational Components

Organizational components are containers for other business components. Oracle ADF Business Components has two kinds of orgainzational components:

Oracle ADF Business Components packages, which are very similar to Java packages (but can contain XML files as well as Java files, and include metadata about the business components they contain)
Oracle ADF Business Components projects, which are very similar to other JDeveloper projects, but also contain information about the datasource connection and certain Oracle ADF Business Components configuration options.

For more information about Oracle ADF Business Components packages and projects, see the related topics list.