"NOT_SUPPORTED_BY_GUI" Exception in JCo

We are having a BAPI that uploads the specified document to SAP.

The BAPI accept three parameters: ID, FILE_LOC and FOLDER_NAME. And I'm setting the values as follows in the JCo code:

JCO.ParameterList paramList = function.getImportParameterList();
paramList.setValue("101XS1", "EXTERNAL_ID");
paramList.setValue("tmp", "FOLDER_NAME");
paramList.setValue("D:/upload/foo.txt", "FILE_LOCATION");

But when I'm trying to execute the BAPI, am getting the following exception:

com.sap.mw.jco.JCO$Exception: (104) RFC_ERROR_SYSTEM_FAILURE: Exception condition "NOT_SUPPORTED_BY_GUI" raised.
    at com.sap.mw.jco.rfc.MiddlewareRFC$Client.nativeExecute(Native Method)
    at com.sap.mw.jco.rf开发者_Go百科c.MiddlewareRFC$Client.execute(MiddlewareRFC.java:1242)
    at com.sap.mw.jco.JCO$Client.execute(JCO.java:3816)
    at com.sap.mw.jco.JCO$Client.execute(JCO.java:3261)

The same BAPI is working fine if I execute through thick client(SAP Logon). But through JCo, its giving this error.

This error in itself does not tell you more than "the ABAP program (function module) raised an exception named NOT_SUPPORTED_BY_GUI". What this really means is probably that the function module tried to access some GUI-related function - which is illegal for BAPIs, so either this is a custom-made RFC function module or you have found a programming error in the SAP standard coding and should open a SAPnet support ticket.

You can't use GUI services in non-gui operations, as RFC or background JOBs. In general avoid use of class cl_gui_frontend_services and functions GUI_*. Alternatively use OPEN_DATASET FOR INPUT/OUTPUT isntruction in your RFC enabled function.

Regards