nameobserver.java

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);
    }
  }
}