Programatically change( edit?? ) JTable cell value

Question

If my user changes the value in cell 'A', I'd like to change the value in cell 'B' to the results of a calculation performed using the new value in A with the present ( prior to changing ) value in B.
Example:
Cell: suggested_sell_price
Cell: cost_this_item
A change in the cost_this_item cell would be reflected in the suggested_sell_price,(upon hitting enter the values are stored in the DB)
Any suggestions would be greatly appreciated,

Answer 1

Thanks for the suggestions. I'm posting a test program of what I have at the moment, it has some of the behavior I'm looking for, but I can't seem to get the new value of an aedited cell and set the table model with the new value.
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
public class TE extends JFrame
     String[] cols = {"VAL_1", "VAL_2", "VAL_3"};
     Object[][] filler = {
                                   {new Double(100.00), new Double(100.00), new Double(100.00)},
                                   {new Double(200.00), new Double(200.00), new Double(200.00)},
                                   {new Double(400.00), new Double(400.00), new Double(400.00)}
     JTable table;
     TE(String title)
               super(title);
               this.setDefaultCloseOperation(EXIT_ON_CLOSE);
               MTM mtm = new MTM(3, cols.length);
               mtm.setColumnIdentifiers(cols);
               int nRows = filler.length;
               for(int i = 0; i < nRows; ++i)
                         mtm.setValueAt(filler[0], 0, i);
                         mtm.setValueAt(filler[1][i], 1, i);
                         mtm.setValueAt(filler[2][i], 2, i);
               table = new JTable(mtm);
               table.getColumnModel().getColumn(1).setCellEditor(new SimpleCellEditor());
               table.getColumnModel().getColumn(2).setCellEditor(new SimpleCellEditor());
               //table.getColumnModel().getColumn(2).setCellEditor(new SimpleCellEditor());
               JScrollPane jsp = new JScrollPane(table);
               Container c = getContentPane();
               c.add(jsp);
               setSize(300,300);
               setVisible(true);
     class MyMouseListener extends MouseAdapter
               public void mouseClicked(MouseEvent e)
                    if(e.getClickCount() == 2)
                              table.setValueAt("QQQQQQQ", 1,1);
class SimpleCellEditor extends AbstractCellEditor implements TableCellEditor, ActionListener
     JTextField tf = new JTextField();
     TableModel tm = table.getModel();
     protected EventListenerList listenerList = new EventListenerList();
     protected ChangeEvent changeEvent = new ChangeEvent(this);
     public SimpleCellEditor()
               super();                              
               tf.addMouseListener(new MyMouseListener());
               tf.addActionListener(this);
public void addCellEditorListener(CellEditorListener listener) {
listenerList.add(CellEditorListener.class, listener);
public void removeCellEditorListener(CellEditorListener listener) {
listenerList.remove(CellEditorListener.class, listener);
protected void fireEditingStopped()
          CellEditorListener listener;
          Object[] listeners = listenerList.getListenerList();
          for (int i = 0; i < listeners.length; i++)
               if (listeners[i] == CellEditorListener.class)
                         listener = (CellEditorListener) listeners[i + 1];
                         listener.editingStopped(changeEvent);
protected void fireEditingCanceled()
     CellEditorListener listener;
          Object[] listeners = listenerList.getListenerList();
               for (int i = 0; i < listeners.length; i++)
               if (listeners[i] == CellEditorListener.class)
                    listener = (CellEditorListener) listeners[i + 1];
                    listener.editingCanceled(changeEvent);
public void cancelCellEditing()
          fireEditingCanceled();
public boolean stopCellEditing()
          fireEditingStopped();
          return true;
public boolean isCellEditable(EventObject event)
          return true;
     public boolean shouldSelectCell(EventObject event)
     return true;
public Object getCellEditorValue()
     return tf.getText();
public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column)
     if(tf.hasFocus() == true)
               tf.setBackground(Color.CYAN);
          return tf;
     public void actionPerformed(ActionEvent e)
          int row = table.getSelectedRow();
          int col = table.getSelectedColumn();
          double nVal = 0.00;
          Object currCostVal;
          Object currSellVal;
          Double costVal;
          Double sellVal;
          double newSellVal;
          double currentCost;
          if(table.getSelectedColumn() == 1)
               currCostVal = table.getValueAt(row, col+1);
               currSellVal = table.getValueAt(row, col);
               costVal = new Double(currCostVal.toString());
               currentCost = costVal.doubleValue();
               sellVal = new Double(currSellVal.toString());
               newSellVal = sellVal.doubleValue();
               nVal = newSellVal*currentCost*100/100;
               System.out.println("Recommended sell-price after change: " + nVal);
          }else if(table.getSelectedColumn() == 2 )
                    currCostVal = table.getValueAt(row, col);
                    currSellVal = table.getValueAt(row, col-1);
                    costVal = new Double(currCostVal.toString());
                    currentCost = costVal.doubleValue();
                    sellVal = new Double(currSellVal.toString());
                    newSellVal = sellVal.doubleValue();
                    nVal = newSellVal*currentCost*100/100;
                    System.out.println("Recommended sell-price after change: " + nVal);
                    System.out.println("Cost column selected " + nVal);
}// end simple cell editor
class MTM extends DefaultTableModel
          MTM(int rows, int cols)
                    super(rows, cols);
public static void main(String args[])
          TE te = new TE("Test of table cell update");