All service call requests for SAP are initiated by the doVerbFor() method in the Java component of the connector module. The connector's ABAP function module /CWLD/RFC_DO_VERB_NEXTGEN and an ABAP handler in the ABAP component of the connector module handle the requests.
Figure 5 illustrates business object processing.
Figure 5. Business
object processing of doVerbFor()
In the Java component of the connector module, the doVerbFor() method of a single business object handler implementation handles all of the business object requests from the integration broker and all business object events from the pollForEvents() method. In either case, doVerbFor() executes in the following manner:
The doVerbFor() method passes business object data to function module /CWLD/RFC_DO_VERB_NEXTGEN and then creates an entirely new business object structure from the returned business object data.
In the ABAP component of the connector module, the connector's ABAP function module /CWLD/RFC_DO_VERB_NEXTGEN is responsible for handling all WebSphere business object processing in the SAP application. Specifically, it routes business object data to the appropriate ABAP handler. In this sense, function module /CWLD/RFC_DO_VERB_NEXTGEN can be thought of as a business object router. It executes in the following manner:
/CWLD/RFC_DO_VERB_NEXTGEN uses ABAP handlers to fulfill each object type and verb-specific request. /CWLD/RFC_DO_VERB_NEXTGEN uses the value in a business object's verb application-specific information to determine which ABAP handler to call. It also checks for the archive status. /CWLD/RFC_DO_VERB_NEXTGEN can be thought of as a router from the doVerbFor() method to an ABAP handler.
ABAP handlers are unique to the connector module in that they extend the business object handler functionality from the Java component of the connector module. ABAP handlers reside in the SAP application as ABAP function modules and communicate directly with /CWLD/RFC_DO_VERB_NEXTGEN. ABAP handlers are needed to get business object data into or out of the SAP application database.
Figure 6 illustrates the business object processing components of the ABAP Extension Module and their relationship to one another. Notice that for a single business object handler (doVerbFor()) and business object router (/CWLD/RFC_DO_VERB_NEXTGEN), there are multiple ABAP handlers.
Figure 6.
Adapter-provided business object processing
components
ABAP handlers are responsible for adding business object data into the SAP application database (Create, Update, Delete) or for using the business object data as the keys to retrieving data from the SAP application database (Retrieve).
The adapter provides generic ABAP handlers. For example, function module /CWLD/DYNAMIC_TRANSACTION supports flat business objects for Create, Update, Delete, and Retrieve operations.
The WebSphere business integration system provides a metadata repository and the adapter provides a generic ABAP handler to support flat business objects. The adapter also provides an ABAP handler (/CWLD/IDOC_HANDLER) to support hierarchical business objects; however, you must develop an additional business-object-specific ABAP handler for each hierarchical business object that you need to support.
The WebSphere business integration system provides tools that facilitate the development process. For more information on developing business objects and ABAP handlers, see Developing business objects for the ABAP Extension module and Appendix D, Generating business object definitions using SAPODA.