Concepts

This section provides information about service composition and the new service composition tool, the Service Composer. The Service Composer perspective represents a combination of an enhanced and more sophisticated design time tool which is integrated with a corresponding runtime environment. It avoids the complexity of customizing a back-end service from customers by providing an easy framework integration between the standard interfaces as Web Service Definition Language (WSDL) - to compose new service interfaces, and Enterprise JavaBeans (EJBs) - to handle service implementations and data transformations.

You can use different sources for back-end services such as RFCs, enterprise services, Web services (including SAP-provided Web services, or ones you have created yourself),and JAX-WS annotated EJBs, as the framework transforms them all in WSDL files.

Following the principles of the SOA concept, the Service Composer goes even deeper then the usual provisioning and consuming of predefined service interfaces and their implementations.

With the Service Composer perspective you can:

1. Simplify existing complex back-end services.

   This allows you to reduce the number of operations, attributes, and data types of a service to meet your requirements.

   Note that when you simplify an existing back-end service interface with Service Composer, you cannot change its original implementation, but you actually create a new service interface (based on an existing one) and provide a new implementation. All the data transformation between attributes of the existing back-end service interface and the new simplified service interface are generated by the tool. Then you can consume this new simplified service as it is, or combine it with others to compose a brand new service.

2. Compose a new service.

   The back-end services that are represented by their service definitions (WSDLs) can be locally imported and then easily consumed using the Service Composer into a single service. This service consumes other back-end services, but additionally you may add new functionality as well.

   Composing the service means that you model the data flow, which is a specific order of execution of the consumed service operations, and also model the data transformation via attribute mappings. As a result, the Service Composer provides a single service (a new service interface and a corresponding implementation) based on the output of multiple back-end services.

The following picture illustrates an example Service Composer use case.

You need to model the data flow and to define the data transformation using attribute mapping between the consumed services.