Before you run your debug-enabled application, replace the optimized
SAP jConnect jconn4.jar file with the debug version
jconn4d.jar, which you can find in the devclasses subdirectory under your SAP jConnect installation
directory.
To set the environment variable:
For UNIX, replace $JDBC_HOME/classes/jconn4.jar with
$JDBC_HOME/devclasses/jconn4d.jar.
For Windows, replace %JDBC_HOME%\classes\jconn4.jar with
%JDBC_HOME%\devclasses\jconn4d.jar.