java.util
Interface Observer

public abstract interface Observer

A class can implement the Observer interface when it wants to be informed of changes in observable objects.

Since:

JDK1.0

See Also:

Observable

Method Summary

void	update(Observable o, Object arg) This method is called whenever the observed object is changed.

Method Detail

update

public void update(Observable o,
                   Object arg)

This method is called whenever the observed object is changed. An application calls an Observable object's notifyObservers method to have all the object's observers notified of the change.

Parameters:

o - the observable object.

arg - an argument passed to the notifyObservers method.