Thread: Simple Publish-Subscribe pattern using J2SE

I am new to Java and was looking into implementing a simple Publish-Subscribe pattern using **only** J2SE and not use any other libraries.

Since i am pretty new to java, all i have done till now is write 3 classes

Main:

 
public class Main {
 
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Subscriber s = new Subscriber();
		Publisher p = new Publisher();
		p.subscribe(s);
 
	}
 
}

Publisher class:

public class Publisher {
 
	/**
	 * @param args
	 */
 
	ArrayList<Subscriber> subscribers = new ArrayList();
 
 
 
	public void subscribe(Subscriber s)
	{
		subscribers.add(s);
	}
 
	public void unsubscriber(Subscriber s)
	{
		subscribers.remove(s);
	}
 
	public void Notify()
	{
		for(int i = 0; i< subscribers.size(); i++)
			subscribers.get(i).update();
	}
 
}

Subscriber class:

public class Subscriber {
 
	/**
	 * @param args
	 */
	public void update()
	{
		System.out.println("here");
	}
}

I understand that they are basic classes but since most of resources which i have found on the web all point to JMS i wasnt able to move forward and have come here.

Any pointers on moving forward would be helpful.

here's some additional info on how the program could work.

*Suppose the following events are specified in the input:*

Subscribe,John,ComputerScience
Subscribe,Sam,Physics
Publish,Dover,Mathematics
Publish,PrenticeHall,Literature
Subscribe,Sam,Literature
Publish,Dover,Physics
Subscribe,Mary,ComputerScience
Publish,PrenticeHall,ComputerScience

*Then the following results can be expected:*

Sam notified of a Physics book from Dover
John notified of a ComputerScience book from PrenticeHall
Mary notified of a ComputerScience book from PrenticeHall
I asked this question even in stack overflow but i never received any answer so i thought i could find some pointers here .. thank you for your time.