第三方

public class TemperatureGUI implements Observable{ ArrayList(<Observable>) observersList = new ArrayList(<Observable>);      public void register (Observer obs) {  observersList.add(obs);}   public void unRegister(Observer obs){ observersList.remove(obs); }   public void notifyObservers(String temperature) {      for (int i = 0; i < observersList.size(); i++) {         Observer observer=(Observer)observersList.elementAt(i);         observer.update (this, temperature); //call update method in all the                                                                     //observers      }   }