Using JViewport with data in 2 classes

I've posted this before, but I posted it in a new thread. This is
because the topic has changed to a JViewport question.

In the below project (incomplete code), I have "columnNames" and
"data" defined in 2 classes for 2 separate tables. I go on to define a
JViewport, so that I can scroll vertically in the right table and the
left table will automatically scroll with the right table.

Should I collapse the 2 sets of "columnNames" and "data" into 1 to get
the scrolling that I want.
Thanks,

package test;

public class ATimer {
   public sttic void ATimer (){}
   public static void startTimer(){
     Timer timer;
     timer = new Timer ();
     timer.schedule (new TheData(),0,5000);
   }
}

public class TheData extends TimerTask{//REALLY UNUSED CLASS
      public void run(){//Data broken up to send to tables separately
      //...
    }
}

class Test extends JFrame{
  public static FixedModel fixedModel;
  public static ModelWithScrollbar mainModel;
  public static JTable fixedTable;
  public static JTable scrollTable;

  public Test (){

    ATimer.startTimer(); // Details omitted

    this.setVisible(true);
    this.setTitle ("An example");

    fixedModel = new FixedModel ();
    fixedTable = new JTable (fixedModel){
    @Override
    public void valueChanged(ListSelectionEvent e){
      super.valueChanged(e);
      checkSelection(true);
    }
   };

   mainModel = new ModelWithScrollbar();

   scrollTable = new JTable (mainModel){
   @Override
   public void valueChanged(ListSelectionEvent e){
     super.valueChanged(e);
     checkSelection(false);
   }
  };

   Dimension dimension = new Dimension(0,0);
   fixedTable.getTableHeader().setPreferredSize(dimension);
   scrollTable.getTableHeader().setPreferredSize(dimension);

   fixedTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
   scrollTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);

   fixedTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
   scrollTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
   scrollTable.setFocusable(false);

   JScrollPane jScrollPane1 = new JScrollPane(scrollTable);

   JViewport viewport = new JViewport();
   viewport.setView(fixedTable);
   viewport.setPreferredSize(fixedTable,getPreferredSize());
   jScrollPane1.setRowHeaderView(viewport);

   jScrollPane1.setCorner(JScrollPane.UPPER_LEFT_CORNER,
                          fixedTable.getTableHea=AD=ADder());
   getContentPane().add(jScrollPane1,BorderLayout.CENTER);
}

//Indirectly called via Timer t
public static void add_Rows_To_Tables (){

   String[] tmp1 = new String [1]; //A, B, C, D, E ,F etc
   String[] tmp2 = new String [10]; //

   //...
   fixedModel.addRow(Arrays.asList(tmp1));
   mainModel.addRow(Arrays.asList(tmp2));

   fixedTable.getSelectionMode().setSelectionInterval(
      fixedTable.getRowCount () - 1,
      fixedTable.getRowCount () - 1);

   scrollTable.getSelectionMode().setSelectionInterval(
      scrollTable.getRowCount () - 1,
      scrollTable.getRowCount () - 1);

   fixedTable.scrollRectToVisible(
      new Rectangle (
        fixedTable.getCellRect(
           fixedTable.getRowCount() - 1,
           0,
           true)));

   scrollTable.scrollRectToVisible(
      new Rectangle (
        scrollTable.getCellRect(
           scrollTable.getRowCount() - 1,
           0,
           true)));
}

private void checkSelection(boolean isFixedTable){
   int fixedSelectedIndex = fixedTable.geSelectedRow();
   int selectedIndex = scrollTable.getSelectedRow();

   if (fixedSelectedIndex != selectedIndex){
      if (isFixedTable){
 
scrollTable.setRowSelectionInterval(fixedSelectedIndex,fixedSelectedIndex);
      } else {

 
fixedTable.setRowSelectionInterval(selectedIndex,selectedIndex);
      }
    }
}

public static main (String[] args){
   Test frame = new Test ();

   frame.addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent e){
         System.exit(0);
      }
    });

    frame.setVisible (true);
   }
}

public class FixedModel extends AbstractTableModel{
   static public List<String> columnNames = new ArrayList();
   static public List<List> data = new ArrayList();

   {
       for (int i = 0;i < 1; i++){
          columnNames.add(" ");
       }
   }

   public void addRow(List rowData){
      data.add(rowData);
      fireTableRowsInserted(data.size() - 1,data.size() - 1);
   }

   public int getColumnCount() {
        return columnNames.size();
      }

      public int getRowCount() {
        return data.size();
      }

      @Override
      public String getColumnName(int col) {
         try {
            return columnNames.get(col);
         } catch (Exception exception) {
            return null;
         }
      }

      public Object getValueAt(int row, int col) {
        return data.get(row).get(col);
      }

      public boolean isCellEditable(int row, int col) {
        return false;
      }

      public Class getColumnClass(int c) {
         return getValueAt(0,c).getClass();
      }
};

public class ModelWithScrollbar extends AbstractTableModel{
   static public List<String> columnNames = new ArrayList();
   static public List<List> data = new ArrayList();

   {
       for (int i = 0;i < 10; i++){
          columnNames.add(" ");
       }
   }

   public void addRow(List rowData){
      data.add(rowData);
      fireTableRowsInserted(data.size() - 1,data.size() - 1);
   }

   public int getColumnCount() {
        return columnNames.size();
      }

      public int getRowCount() {
        return data.size();
      }

      @Override
      public String getColumnName(int col) {
         try {
            return columnNames.get(col);
         } catch (Exception exception) {
            return null;
         }
      }

      public Object getValueAt(int row, int col) {
        return data.get(row).get(col);
      }

      public boolean isCellEditable(int row, int col) {
        return false;
      }

      public Class getColumnClass(int c) {
         try {
            return getValueAt(0,c).getClass();
         }
         catch (Exception exception) {// MAY LEAD TO ERROR
            return this.getClass();
         }
      }
};