What are the Examples of Observer Design Pattern in JDK ?
In JDK there are many places where Observer design pattern is used. Some of these are..
1 - java.util.Observer, java.util.Observable
2 - javax.servlet.http.HttpSessionAttributeListener
3 - javax.servlet.http.HttpSessionBindingListener
4 - All implementations of java.util.EventListener, and also in Swing packages
5 - javax.faces.event.PhaseListener