Need a help on TableModelListener.

We can do sum calculation directly in the TableModel. The method "setValueAt" of the TableModel is called after each cell editing. We can override it to do anything we want with the old value stored in the model and the new value passed into the method through the parameter list. When deleting a row, we also call some method of the model (something like "removeRow") and there again we can do anything we like with the old value before deleting it.