JCo RFC Provider Service
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 a 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).
This section explains how the JCo RFC Provider works within the J2EE Engine environment.
RFC Scenario

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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.

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.

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.
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, see Registering a Destination.
You then have to write a bean with a processFunction(Function <name>) method. When this bean is deployed you can call its function from inside the Web AS and specify input parameters depending on the tasks you want to perform. The bean receives these parameters, accomplishes the tasks, and returns the result, which will be displayed in the Web AS when starting the connection.
You can use the JCo RFC Provider service to connect to the CCMS system. For more information, see Connecting J2EE Engine to the CCMS.
The JCo RFC Provider service supports SSO Tickets. That is, if in the ABAP environment the corresponding RFC destination is configured to send a SSO Ticket, during a Function Call “ABAP-J2EE Engine” this SSO ticket will be received. This will activate the process of authorizing the user. For more information, see Configuring the J2EE Engine to Accept Logon Tickets.
The service also provides you the possibility to define particular RFC destinations to use Secure Network Connection (SNC). For more information, see Configuring an RFC Destination to use a Secure Network Connection (SNC).
See also:
JCo RFC Provider Service Properties in the Reference Manual