A gateway service is built using 2 ABAP classes: Data Provider Class and Model Provider Class.
Data Provider Class – contains the implementation of the service’s functionality.
Model Provider Class – provides metadata about the service.
These 2 classes do not communicate with each other. They are linked using configuration.
Two configuration wrappers are created for each of the above classes.
Service Group – configuration wrapper for the Data Provider Class. Contains the internal and external service name. Note that the external name can be different and need not start with Z. By default, SAP sets both of them as the same.
Technical Model Object – configuration wrapper for the Model Provider Class.
A service is complete when we associate the Service Group and the Technical Model Object. This is shown in the diagram below.
Finally, the service needs to be added to the service catalog.
Use of Sybase’s Unwired Platform is not mandatory for consuming Gateway services. Any language can be used, as long as it supports read data from XML and via HTTPS.