code: public JLabel getTableCellRendererComponent(final JTable table, 
                                                  final Object value, 
                                                  final boolean isSelected, 
                                                  final boolean hasFocus, 
                                                  final int row, 
                                                  final int column) {
              
          final String str = (value == null) ? "NULL" : value.toString();
          final JLabel cell = new JLabel(str);
              
          cell.setForeground((value == null) ? Color.LIGHT_GRAY : Color.BLACK);
              
          return cell;
      }
docs: {@inheritDoc}