/** * See page 294 of DESIGN PATTERNS [1995]. * Implemented by Blueprint Technologies, Inc. */ /** * Package */ package com.blueprint.patterns.gamma.behavioral.observer; /** * Maintains a reference to a ConcreteSubject object. Stores * state that should stay consistent with the subject's. * Implements the Observer updating interface to keep its * state consistent with the subject's. */ public class ConcreteObserver implements Observer { public void update() { System.out.println( "update() called." ); } }