RFC call failing due to UNICODE implementation


We are trying to connect to a SAP system using the JCO (SAP-JAVA Connectivity). We are passing the user name as an input parameter and in turn the SAP system send back the no. of item (ABAP Type integer) pending for the user name to the java and its inserted/updated in Oracle DB (which does accept the unicode characters).

It was all wokring fine untill the SAP system has been migrated to Unicode upgrade. Now the RFC call is getting failed from our system. On analysis we found with debug, that the user name is not getting accepted by the SAP system and throwing the error -says Exception in thread "main" com.sap.aii.proxy.framework.core.BaseProxyException: Conversion error between two character sets., error key: RFC_ERROR_SYSTEM_FAILURE and at the SAP end the error says "Conversion of "UNAME" from code page 4103 to 4102 is failed". The unicode change in SAP system cannot be reverted back due to some constraints.

Can you please help, how can we pass the user name as encoded in character set 4102 or any other solution so that it can be accepted by SAP and run the Function module and return the data.

Many Thanks

Snehil Joshi