ABCS as a Composite Application How Many Components Need to Be Built

12-4 Developers Guide for Oracle Application Integration Architecture Foundation Pack – Data element spreadsheet mapping between the EBO and participating application messages. – Operations mapping between the EBS and participating applications. ■ The style of interaction MEP: request-response, fire and forget, asynchronous request, and delayed response is defined. See Section 11.3.2, Choosing the Appropriate MEP . ■ The communication protocols with the participating applications are identified. For more information about how an ABCS interacts with participating applications, see the sections in Chapter 21, Establishing Resource Connectivity. ■ Any participating application-specific requirements such as error handling or security have been identified.

12.1.2 ABCS as a Composite Application

AIA services ABCSs and EBSs can be developed as a composite application built using SCA building blocks. Four SCA elements apply to these services: ■ Service Represents an entry point into the SCA component or a composite. ■ Reference Represents a pointer to an external service outside the scope of the given SCA component. ■ Implementation type Defines the type of implementation code for a given SCA component that is used for coding the business logic. Example implementation types include BPEL and Mediator. ■ Wire Represents the mechanism by which two components can be connected to each other. Usually a reference of one component is connected to a service exposed by another component. An SCA component may expose one or more services, may use one or more references, may have one or more properties defining some specific characteristics, and may be connected to one or more components using SCA wiring. The building blocks of SCA can be combined and assembled to create composite applications. A composite application can be thought of as a composition of related SCA components that collectively provide a coarse-grained business function.

12.1.3 How Many Components Need to Be Built

A composite application can be thought of as a composition of related SCA components that collectively provide a coarse-grained business function. A composite may contain certain components that might be required only for the internal implementation of the composite and for which interfaces might not be required outside the scope of the composite in context. Components may exist that can be used just for the internal implementation of the composite and are thus not required to expose services, references, or both. Constructing the ABCS 12-5 A requester ABCS composite as shown in Figure 12–1 can be built using a single component that is exposed as service. The component can use one reference representing an EBS or more references representing the outbound interactions with other applications. Figure 12–1 Example of a Requester ABCS Composite Similarly, a Provider ABCS composite as shown in Figure 12–2 can be built using a single component that is exposed as service. The component can use one or more references representing the outbound interactions with the applications. Figure 12–2 Example of a Provider ABCS Composite

12.2 Constructing an ABCS Using Service Constructor