Introduction to Interface Development

Interfaces are at the heart of every cross-component process. They are referenced almost constantly during design and configuration. For this reason, it is vital that an interface description can be accessed at a central point. The following are interface description types that you can save in the Integration Repository:

· Platform-independent message interfaces

· Imported interfaces for which an XML representation of a BAPI, RFC, or IDoc is generated in the Integration Repository

· External WSDL, XSD, or DTD definitions containing message schemas that you can access in the Integration Builder

For all three types, the Integration Repository only contains information about their structure (interface type, parameters used, and data types) and not about how the interfaces are actually implemented. By keeping this information separate, you can access the interface descriptions when defining integration scenarios, integration processes, mappings, or in routing, without having to communicate with the systems in which the interfaces are implemented.

In the context of the Integration Builder and in this documentation, we only refer to interfaces (for example, message interfaces or imported interfaces) and not to interface descriptions.

Prerequisites

The interface types you use for the integration of your collaborative process depend on the process itself and your system landscape. Usually, you will have to use different interface technologies for the integration process. The following technical restrictions exist:

Prerequisites for Proxy Generation from Message Interfaces

Target Language	Version of Platform Required to Implement Proxies
ABAP	SAP systems based on SAP Web AS 6.40
Java	J2EE applications: SAP J2EE Engine 6.40 and higher

To connect RFCs, BAPIs, and IDocs originating from systems Release 3.1I or higher to SAP Exchange Infrastructure, you require either the RFC adapter or the IDoc adapter. You can import RFCs, BAPIs, and IDocs to the Integration Repository from Release 4.0 and higher (for more information, see the Prerequisites section in Importing IDocs and RFCs). To integrate non-SAP systems you require the Adapter Engine, which can forward messages as files to the Integration Engine, for example.

It is of course still possible to develop RFCs, BAPIs, and IDocs after SAP Web AS 6.40 and to use relevant adapters to integrate them. However, we recommend that you use message interfaces for new developments.