It seems that with Oracle that SCHEMA is analogous to the DBMS user.
So changing line 341 in Jenny.java.
From:
ResultSet results = metaData.getTables( null , null , "%" , new String[]{"TABLE"} );
To:
ResultSet results = metaData.getTables( null , userName , "%" , new String[]{"TABLE"} );
limited Jenny to the tables for the specified userName instead of trying to parse through all tables for all users.