Redefining a method

Question

Is it possible to redefine a method of a class within an already instantiated instance of that class? For example if I have ...
class Dog{
  public boolean isBigDog(int width, int height){
    return true;  // always says its a big dog
  public void sitOnCouch(){
     if(isBigDog(with,height){
       System.out.println("Dog can sit on the couch");
     }else{
       System.out.println("Dog CAN'T sit on the couch");
public static void main(String[] args){
  Dog dog = new Dog();
  dog.sitOnCouch();  // prints out "Dog can sit on the couch"
  //now if I didn't want that same dog, not a new one, to sit on the couch how can I redefine isBigDog()
  //for that instance of dog?
}What I am really trying to do is to redfine the isCellEditable(int row, int col) in the DefaultTableModel class on an already instantiated DefaultTableModel. User click's a check box to allow cells to be editable or not to be editable.

Answer 1

AwhHawh.... GOT IT! In case anyone cares for this
bit of code it will "change cell editable on the fly".Not bad at all. However it has the side effect of creating a whole new model and throwing away
the old one. Let me suggest this instead, as per my previous post recommending a subclass:public class MyDefaultTableModel extends DefaultTableModel {
  // local variable to store "editable" status
  private boolean isEditable = true;
  public MyDefaultTableModel(Object[][] data, Object[] columnNames) {
    super(data, columnNames);
  public DefaultTableModel(Object[] columnNames, int rowCount) {
    super(columnNames, rowCount);
  // implement any other constructors you need like the above
  // method to change "editable" status
  public void setAllowEditing(boolean allow) {
    isEditable = allow;
  // override isCellEditable to use our private variable
  public boolean isCellEditable(int row, int column) {
    return isEditable;
}Hope this helps.
PC²