see also
JavaIdioms
ObserverObservable is Java's implementation of the
ObserverPattern from the
GangOfFour book,
DesignPatterns.
Observable is a class that implements the GoF's "subject" methods (i.e. addObserver(), removeObserver(), notifyObservers().
Observer is an interface that defines an "update()" method.
The Java Swing GUI uses the
ObserverPattern for communication with the widgets, but does not use Java's own
ObserverObservable classes. Observers are called (event) listeners, and Swing relies on a set of method naming conventions (e.g. addListener()), instead of a common implementation.
CategoryJava