SwingUtilities.invokeLater(new Runnable() {
                         public void run() { 
                             try {
                                jTable1.setModel(new JDBCTableModel (conn, (String)jComboBox1.getSelectedItem()));
                            } catch (SQLException e) {
                                // TODO Auto-generated catch block
                                e.printStackTrace();
                            }
                        }
                    });