[代码][Java]代码
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import java.util.Observable;public class House extends Observable { private float price; public House(float price) { this.price = price; } public float getPrice() { return price; } public void setPrice(float price) { super.setChanged(); //设置变化点 super.notifyObservers(price); //发出变化通知 this.price = price; } @Override public String toString() { return "房子的价格为:" + price ; } } |
2. [代码][Java]代码
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import java.util.Observable;import java.util.Observer;public class Buyer implements Observer{ private String name; public Buyer(String name) { this.name = name; } @Override public void update(Observable observable, Object object) { if (object instanceof Float) { System.out.print(this.name + "观察到价格变化："); System.out.println(((Float)object).floatValue()); } } |
3. [代码][Java]代码
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public class TestMain { /** * @param args */ public static void main(String[] args) { House house = new House(1000f); Buyer b1 = new Buyer("A"); Buyer b2 = new Buyer("B"); Buyer b3 = new Buyer("C"); house.addObserver(b1); house.addObserver(b2); house.addObserver(b3); System.out.println(house); house.setPrice(6000.0f); System.out.println(house); }} |
