subject.java~

designpatterns for aop

package designpatterns.observer.java;


public interface Subject {
    
    /**
     * Attaches an <i>Observer</i> to this <i>Subject</i>.
     */
    public void addObserver(Observer o);

    /**
     * Detaches an <i>Observer</i> from this <i>Subject</i>.
     */
    public void removeObserver(Observer o);

    /**
     * Notifies all <i>Observer</i>s.
     */
    public void notifyObservers();
}