Howdy, Carlos!
Well, personally, I don't like NetBeans (this is just, of course, a personal opinion), so I don't know exactly how your environment is. But the thing is, in order to refresh the JTable so it displays the data of your TableModel,
you should call fireTableDataChanged() after updating the TableModel.
Cheers, Roberto Perillo
SCJP, SCWCD, SCJD, SCBCD