SAP Gateway serves as a bridge between SAP backend systems and external applications, enabling seamless communication via standard protocols such as OData. A critical aspect of SAP Gateway integration is the ability to connect to ABAP systems and execute business logic efficiently. This connection is primarily achieved through Remote Function Calls (RFCs) and Business Application Programming Interfaces (BAPIs)—two core technologies within the SAP ecosystem that allow remote interaction with ABAP programs and business objects.
RFC is a communication interface in SAP that allows a program to call functions in a remote SAP system or between processes within the same system. It is the underlying technology for enabling remote communication and integration.
BAPIs are standardized programming interfaces representing business objects in SAP. They provide stable and documented methods to perform business operations such as creating a sales order, changing customer data, or posting a goods receipt.
SAP Gateway exposes SAP backend functionality via OData services. To fulfill service operations such as Create, Read, Update, Delete (CRUD), it often needs to invoke backend logic. This backend logic typically resides in:
By leveraging RFCs and BAPIs, SAP Gateway can act as a secure, scalable interface layer, enabling external clients (mobile apps, Fiori apps, third-party systems) to interact with SAP’s business logic in a controlled manner.
OData Service Implementation
In the Data Provider Class (DPC_EXT), OData operations (like CREATE_ENTITY, READ_ENTITYSET) are implemented in ABAP.
Calling RFCs or BAPIs
Inside these methods, the service calls relevant RFC-enabled function modules or BAPIs to process the business logic.
Example:
CALL FUNCTION 'BAPI_SALESORDER_CREATEFROMDAT2'
EXPORTING
order_header_in = ls_order_header
TABLES
order_items_in = lt_order_items
return = lt_return.
Handling Responses
The RFC/BAPI responses are processed and mapped back to the OData response payload, ensuring consistent data exchange.
Transaction Handling
When multiple calls or updates are involved, transaction management (commit/rollback) is handled via BAPI transaction functions:
CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
EXPORTING wait = 'X'.
CREATE_ENTITY method is triggered.BAPI_SALESORDER_CREATEFROMDAT2 is called via RFC.BAPI_TRANSACTION_COMMIT) is called.RFCs and BAPIs form the backbone of SAP Gateway’s integration with ABAP backend systems. By leveraging these technologies, SAP Gateway enables powerful, secure, and efficient access to SAP business logic for modern applications. Understanding and utilizing RFCs and BAPIs effectively is essential for SAP developers and architects building scalable OData services.