Subject.java.
- By Robert C. Martin
- August 16, 2001
Uncle Bob's Agile Development Corner
OBSERVER—Evolving into a pattern, Part 2
by Robert C. Martin
Listing 9. Subject.java.
import java.util.*;
public class Subject
{
private Vector itsObservers = new Vector();
protected void notifyObservers()
{
Iterator i = itsObservers.iterator();
while (i.hasNext())
{
Observer observer = (Observer) i.next();
observer.update();
}
}
public void registerObserver(Observer observer)
{
itsObservers.add(observer);
}
}
About the Author
Robert C. Martin is president of Object Mentor Inc., a firm that offers high-level, OO software design consulting, training, and development services. He is the author of Designing Object Oriented C++ Applications Using the Booch Method. He can be contacted at [email protected].