設計模式之觀察者模式

 先附上觀察者模式的一個測試代碼。

有空再仔細寫一下。

package com.hbq.test;

import java.util.ArrayList;

/*觀察者模式*/
/*觀察者接口*/
interface Observer
{
    public void update(String context);
}

interface Observable
{
    public void addObserver(Observer obj);
    public void deleteObserver(Observer obj);
    public void notifyObserver(String context);
}

class Hanfeizi implements Observable
{
    ArrayList<Observer> observer = new ArrayList();

    @Override
    public void addObserver(Observer obj) {
        // TODO Auto-generated method stub
        this.observer.add(obj);
    }

    @Override
    public void deleteObserver(Observer obj) {
        // TODO Auto-generated method stub
        this.observer.remove(obj);
    }

    @Override
    public void notifyObserver(String context) {
        // TODO Auto-generated method stub
        for( Observer obj:observer)
        {
            obj.update(context);
        }
    }

    public void haveFun()
    {
        System.out.println("韓非子：開始娛樂啦...");
        this.notifyObserver("韓非子在娛樂！");
    }

    public void haveBreakfast()
    {
        System.out.println("韓非子：開始吃飯啦...");
        this.notifyObserver("韓非子在吃飯！");
    }

}

class Lisi implements Observer
{

    @Override
    public void update(String context) {
        // TODO Auto-generated method stub
        System.out.println("李斯：觀察到韓非子活動啦，開始向老闆彙報....");
        this.reportToQinshihuang(context);
        System.out.println("李斯：彙報完畢，秦老闆賞給他兩個蘿蔔吃吃....\n");
    }

    public void reportToQinshihuang(String repContext)
    {
        System.out.println("李斯：報告，秦老闆！韓非子有活動啦--->"+repContext);
    }
}

class Wangsi implements Observer
{

    @Override
    public void update(String context) {
        // TODO Auto-generated method stub
        System.out.println("王四：觀察到韓非子活動啦，開始向老闆彙報....");
        this.reportToQinshihuang(context);
        System.out.println("王四：彙報完畢，秦老闆賞給他兩個蘿蔔吃吃....\n");
    }

    public void reportToQinshihuang(String repContext)
    {
        System.out.println("王四：報告，秦老闆！韓非子有活動啦--->"+repContext);
    }
}

class Zhangsi implements Observer
{

    @Override
    public void update(String context) {
        // TODO Auto-generated method stub
        System.out.println("張四：觀察到韓非子活動啦，開始向老闆彙報....");
        this.reportToQinshihuang(context);
        System.out.println("張四：彙報完畢，秦老闆賞給他兩個蘿蔔吃吃....\n");
    }

    public void reportToQinshihuang(String repContext)
    {
        System.out.println("張四：報告，秦老闆！韓非子有活動啦--->"+repContext);
    }
}

public class test {

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Observer lisi = new Lisi();
        Observer wangsi = new Wangsi();
        Observer zhangsi = new Zhangsi();

        Hanfeizi hanfeizi = new Hanfeizi();

        hanfeizi.addObserver(lisi);
        hanfeizi.addObserver(wangsi);
        hanfeizi.addObserver(zhangsi);

        hanfeizi.haveFun();

        hanfeizi.haveBreakfast();
    }

}