23种GOF模式的java代码实现

				package org.gof.action.observer;
				
				import java.util.Observer;
				import java.util.Observable;
				
				//观察者NameObserver主要用来对产品名称(name)进行观察的
				public class NameObserver
				    implements Observer {
				
				  private String name = null;
				
				  public void update(Observable obj, Object arg) {
				
				    if (arg instanceof String) {
				
				      name = (String) arg;
				      //产品名称改变值在name中
				      System.out.println("NameObserver :name changet to " + name);
				    }
				  }
				}