Look for the return value from executeUpdate call. Is it really returning 0? If not so, then probably the autocommit on your connection is false. So you may have to call
before closing statement object.
If, executeUpdate call returns 0, then I am not sure why you did not get any exception.
It is very good that executeUpdate returns 1. Now, try putting con.commit() before closing statement object, as I have suggested before. Looks like, connections are not set to autocommit on your database and you do have to do it as part of your program.
You may talk to your DBA (or look for documentation to see how if you are DBA yourself) if database connections are set to have autocommit false by default.