java: 观察者模式:Observable被观察者,Observer观察者
以房子价格为例,卖房者为被观察者:
import java.util.Observable;
//被观察者子类化
public class House extends Observable {
private float price;...
GOF给出的定义:
Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.
定义了对象之间的一种一对多的依赖关...