[Design Pattern] Observer

Java

<I>Subject

public interface Subject{
            public void register (Observer anObserver) ;
            public void unregister (Observer anObserver) ;
            public void notifyObservers () ;
} 

<I>Observer 

public interface Observer{
            public void update(Data dataUpdate.....);
}

 

SUBJECT.JAVA

01	// This interface handles adding, deleting and updating

02	// all observers

03

04	public interface Subject {

05

06	public void register(Observer o);

07	public void unregister(Observer o);

08	public void notifyObserver();

09

10

}

OBSERVER.JAVA

view sourceprint?

1	// The Observers update method is called when the Subject changes

2

3	public interface Observer {

4

5	public void update(double ibmPrice, double aaplPrice, double googPrice);

6

7

}

- See more at: http://www.newthinktank.com/2012/08/observer-design-pattern-tutorial/#s