How do I get Integer in JTable cell to be selected when edit using keyboard

Question

I have some cells in a JTable, when I double-click on the cell to edit it the current value (if any) is selected and is replaced by any value I enter, which is the behaviour I want. But when I use the keyboard to navigate to the cell and start editing, new values are added to the end of the current value which is not what I want.
I have created my own IntegerCellEditor (see below) and added a focus event or the textfield used when editing to select all the current text but it has no effect, any ideas please ?
public class IntegerCellEditor extends DefaultCellEditor
    public IntegerCellEditor( JTextField textfield )
        super( textfield );    
        //Ensure old value is always selected, when start editing
        ((JTextField)getComponent()).addFocusListener(new FocusAdapter()
                public void focusGained(FocusEvent fe){
                    ((JTextField)getComponent()).selectAll();
        ((JTextField)getComponent()).setHorizontalAlignment(JTextField.RIGHT);
     * Return as Integer (because delegate converts values to Strings).
    public Object getCellEditorValue()
        return Integer.valueOf((String)delegate.getCellEditorValue());
}

Answer 1

But when I use the keyboard to navigate to the cell and start editing,
new values are added to the end of the current value which is not what I want.How does the use know that typing will replace the text and not append? Usually if text is to be deleted, it is highlighted to give the user a visual cue.
Here is a renderer that does this, in case your interested:
http://forum.java.sun.com/thread.jspa?forumID=57&threadID=752727