JAVA设计模式之观察者模式

ObserverManager接口：

package com.zg.service;

public interface ObserverManager {

    public abstract void addObserver(Observer observer);
    public abstract void removeObserver(Observer observer);
    public abstract void action();

}

 

ObserverManagerImpl 接口实现类：

package com.zg.service;

import java.util.Vector;

public class ObserverManagerImpl implements ObserverManager {
    
    Vector<Observer> observers;
    
    public ObserverManagerImpl() {
        observers = new Vector<Observer>();
    }
    
    
    @Override
    public void addObserver(Observer observer) {
        observers.add(observer);
    }

    @Override
    public void removeObserver(Observer observer) {
        for (Observer obs : observers) {
            if (obs.equals(observer)) {
                observers.remove(obs);
            }
        }
    }


    @Override
    public void action() {
        for (Observer obs : observers) {
            obs.startTask();
        }
    }

}

 

Observer 类：

package com.zg.service;

public interface Observer {

    public abstract void startTask();
}

 

OneObserver 1号观察者：

package com.zg.service;

public class OneObserver implements Observer {

    @Override
    public void startTask() {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println("我是1号观察者，我观察到数据正在变化，我要处理事情....");
            }
        });
        thread.start();
    }

}

 

TwoObserver 2号观察者：

package com.zg.service;

public class TwoObserver implements Observer {

    @Override
    public void startTask() {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                System.out.println("我是2号观察者，我观察到数据正在变化，我要处理事情....");
            }
        });
        thread.start();
    }

}

 

 

Test 测试一下：

package com.zg.service;

public class Main {

    public static void main(String[] args) {
        ObserverManager observerManager = new ObserverManagerImpl();
        OneObserver oneObserver = new OneObserver();
        TwoObserver twoObserver = new TwoObserver();
        
        observerManager.addObserver(oneObserver);
        observerManager.addObserver(twoObserver);
        observerManager.action();
    }
}

 

输出结果：

我是1号观察者，我观察到数据正在变化，我要处理事情....
我是2号观察者，我观察到数据正在变化，我要处理事情....