Not Really a Blog

January 29, 2006

About FON

Filed under: Internet, Random, Sussex University — Tags: , — jesus @ 21:00

As part of my studies in my e-business
course at the University of Sussex, I have been asked to write a report of a company that is somehow involved with e-business (e-commerce, use of technology to become more profitable or efficient, etc.).

So, I have decided that I am going to do some research on FON, a company created by Martin Varsavsky who is famous for founding Jazztel and Ya.com, one of the biggest phone companies and ISP in Spain.

FON idea is to profit from creating a network of wireless users around the world, called the p2p of wifi.

My task is, first of all, writing a background briefing report about the company, and afterwards an investment recomendation based on my research and study of the subject.

I chose this company because I have a friend who is working there and because I think it is interesting to see if FON’s business model is profitable or not. By the way, I have no access to internal sources as Teo (hi Teo!!) is quite secretive about it (I think because of NDAs).
Anyway, I’ll post more about it in the near future, I guess. Stay tuned.

January 28, 2006

On Distributed Computing using RMI

Filed under: Programming, Sussex University — Tags: , — jesus @ 17:40

Ok, so I have this assignment in one of my courses at the University of Sussex, Distributed Systems. The thing is that we need to implement a distributed event notification system, in which clients subscribe themselves to the server to which some event generators sends their events.

All of this, using RMI (Remote Method Invocation) in Java.

The assignment is an introduction to distributed objects in java by implementing this little system. In it, each Event Generator, sends events to the server, made of an identification string and a message (in fact, it could be any kind of object).

On the other hand, the server get subscriptions of clients. These send the server a regular expression and a timeout, each of which would be used to choose among the different events received and to set a maximu time in which the subscription is valid. When doing so, the server sets up a callback function to the clients so, when a matching event is received, the server has a way to send the clients the object (event). I think it can be better understood by looking at the graph above.

So far, it’s been quite interesting to learn this kind of distributed framework, although java is not my kind of language. I want to do some more researh on how to do this kind of things with other languages like ruby o r python. Seems to me interesting.

Here is a little bit of the code used, just for curiosity:

public static void main(String[] args) {
	if (System.getSecurityManager() == null) {
	System.setSecurityManager(new RMISecurityManager());
	}
	try {
		EventNotificationServer server = new EventNotificationServerImpl();
		String hostName = InetAddress.getLocalHost().getHostName();
		Naming.rebind("//" + hostName + "/"
				+ EventNotificationServer.rmiName, server);
		System.out.println("EventNotificationServerImpl bound to "
				+ hostName);

	} catch (Exception e) {
		System.err.println("EventNotificationServerImpl exception: "
				+ e.getMessage());
		e.printStackTrace();
	}

}

The assignment is an introduction to distributed objects in java by implementing this little system. In it, each Event Generator, sends events to the server, made of an identification string and a message (in fact, it could be any kind of object).

On the other hand, the server get subscriptions of clients. These send the server a regular expression and a timeout, each of which would be used to choose among the different events received and to set a maximum time in which the subscription is valid. When doing so, the server sets up a callback function to the clients so, when a matching event is received, the server has a way to send the clients the object (event). I think it can be better understood by looking at the graph above.

So far, it’s been quite interesting to learn this kind of distributed framework, although java is not my kind of language. I want to do some more researh on how to do this kind of things with other languages like ruby o r python. Seems to me interesting.

Here is a little bit of the code used, just for curiosity:

public static void main(String[] args) {
    if (System.getSecurityManager() == null) {
    System.setSecurityManager(new RMISecurityManager());
    }
    try {
        EventNotificationServer server = new EventNotificationServerImpl();
        String hostName = InetAddress.getLocalHost().getHostName();
        Naming.rebind("//" + hostName + "/"
                + EventNotificationServer.rmiName, server);
        System.out.println("EventNotificationServerImpl bound to "
                + hostName);

    } catch (Exception e) {
        System.err.println("EventNotificationServerImpl exception: "
                + e.getMessage());
        e.printStackTrace();
    }
}

January 11, 2006

On XML and Java

Filed under: Programming, Random — Tags: , — jesus @ 20:40

As part of an
assignment
for a course at Sussex University I have to create a Servlet to run a small application, one to deal with a wedding list. It involves quite a few technologies, including XML, javascript, CSS and JAVA.So far I am not specially happy with the course as I haven’t enjoyed it as much as I thought initially.

I think it is because there are so many technologies considered in such a short period of time, but I think that Java itself made me feel very uncomfortable from the very beginning (As an example, I found the Java DOM API to be quite awkward to use). Anyway.

But I must admit that I have learned some topics I was not proficient in, such as javascript, css and XML.

Probably I would feel much better doing these things in a scripting language such as python or ruby, or even perl…

So far I am not specially happy with the course as I haven’t enjoyed it as much as I thought initially.

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