Easier way to set post-constructor JTable column names?

Question

I have a class that extends JTable. It also has a pair of inner classes that extend DefaultTableCellRenderer and AbstractTableModel so I can dynamicaly adjust the number of rows and their contents. That's not the problem - that part works fine. The problem is the column headers. My table doesn't currently have any but I want to add them.
The column quantity is constant at 3 and should always be the same 3 Strings. It would be nice if I could use the JTable constructors that take a Vector or Object[] of column names from the start in my new class' constructor. But I don't think I can because at that point I don't know how many rows there will be or what they'll contain. Trying to set rowData to null just caused runtime exceptions.
So the alternative seems to be to call setColumnModel() within the constructor, passing it a DefaultTableColumnModel. Which then requires I call addColumn() three times. Each time passing it a new TableColumn object. Each of which requires that I separately call setHeaderValue() after I construct it to set the header name. Am I right in that is the only way to do it? It just seems overly complex.

Answer 1

I'll post a streamlined version of my class in case that will help...
public class TotalsTable extends JTable
   private static int NUM_COLUMNS = 3;
   static final public String columnNames[] = {
         "Col Name 1", "Col Name 2", "Col Name 3"};
   protected Vector data = null;
   private TotalsModel tableModel;
   public TotalsTable()
      tableModel = new TotalsModel();
      setModel(tableModel);
      TableCellRenderer renderer = new TotalsCellRenderer();
      setDefaultRenderer(Object.class, renderer);
   public void updateTable(Vector pData)
      data = pData;
      tableModel.update();
   class TotalsCellRenderer extends DefaultTableCellRenderer
      public Component getTableCellRendererComponent
         (JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
         super.getTableCellRendererComponent(table, value, isSelected,
                                             hasFocus, row, column);
         if (column == 0) {
            setForeground(Color.blue);
         else {
            setForeground(Color.black);
         return this;
   class TotalsModel extends AbstractTableModel
      public TotalsModel()
         super();
      protected void update()
         fireTableStructureChanged();
       * Retrieves number of columns
       * (Necessary for AbstractTableModel implementation)
      public synchronized int getColumnCount()
         return NUM_COLUMNS;
      public synchronized int getRowCount()
         if (playerData == null)
            System.out.println("No rows found in table");
            return 0;
         else
            return playerData.size();
       * Returns cell information of a record at location row,column
       * (Necessary for AbstractTableModel implementation)
      public synchronized Object getValueAt(int row, int column)
         try
            MyObject p = (MyObject) data.elementAt(row);
            switch (column)
               case 0:
                  return p.getName();
               case 1:
                  return ("" + p.getDataItem2());
               case 2:
                  return ("" + p.getDataItem3());
               default:
                  System.out.println("getValueAt() Error: Invalid column");
         catch (Exception e)
            System.out.println("Exception in getValueAt(): " +
                               e.getMessage());
         return "";
      public String getColumnName(int col)
         if (col < NUM_COLUMNS)
            return columnNames[col];
         else
            return "";
      public Class getColumnClass(int c)
         return getValueAt(0, c).getClass();
}