public int compare(T a,T b){
  Object o1=a.getValueAt(_activeColumn);
  Object o2=b.getValueAt(_activeColumn);
  return AbstractTableMediator.compare(o1,o2) * _ascending;
}

public int compare ( T a , T b ) { Object o1 = a . getValueAt ( _activeColumn ) ; Object o2 = b . getValueAt ( _activeColumn ) ; return AbstractTableMediator . compare ( o1 , o2 ) * _ascending ; }
a generic compare function .
