JCo RFC Connection

The RFC is an SAP interface protocol, which simplifies the programming of communication processes between systems. The RFCs enable you to call and execute predefined functions in a remote system, or in the same system. The RFCs manage the communication process, parameter transfer, and error handling.

In the J2EE Engine the RFC functions are implemented by the JCo RFC Provider service, which is used for processing ABAP to Java requests. A feature is provided for receiving calls from the SAP systems – this is done by registering the J2EE Engine as an RFC destination.
The JCo RFC Provider Service processes calls from the SAP systems. It dispatches the calls to a stateless session bean, which is registered in the J2EE Engine naming system. By naming convention the JNDI name used is identical to the name of the SAP function module.
Technically, the service is based on the JCo (SAP Java Connector).

The JCo RFC Provider service uses a TCP/IP connection type. Hence, the destination must be created in the Web AS with a gateway host and gateway service for the particular system. Then, on the J2EE Engine, the same destination with the same name, host,
and service is created. For more information about registering destinations on J2EE Engine

SAP Web AS with the SAP Java Connector as the interface between the J2EE and the ABAP environment:


1.  On startup the JCo RFC Provider service connects to the Web AS repository.

2.  On startup the JCo RFC Provider service registers itself at the Gateway with a defined name.
 It is possible to register it under different names and at different Gateways.

3.  The Web AS calls a function for the registered RFC destination.

Note: Make sure that the function is defined in the repository!

4.  The Gateway forwards the call to the JCo RFC Provider service.

5.  The JCo RFC Provider service looks in the JNDI for the EJB, which is registered under the function name.

Note: The name of the function must be identical with the JNDI name of the bean, that is, it is necessary to have a JNDI name. If there is no such name, the JCo RFC Provider service will not be able to find the bean.

It is advisable for the beans to be written with a LocalHome interface.

6.  The JCo RFC Provider service calls the processFunction(JCO.Function) method of the EJB found.

  7.  The results of that call (the modified JCO.Function) are passed to the Gateway.

  8.  The Gateway passes the results back to the Web AS.