Lesson 10 - Bits and pieces

[Datapunter]

Lesson 10 ( Word document )

Punters Lounge JAVA programming course.
Lesson 10 - Bits and pieces.

Well, we’re almost there.
Just a few more bits and pieces and you can call yourself a JAVA programmer.


10.1 Being responsible about accessing Web sites.

A little word about being responsible about accessing the web. Now you may think “what ?”
I’ll access the web any way I want thank you, no need to tell me about responsibility.

Well, i’ll have a word about it anyhow.

First there is the matter of copyright. A lot of information on web sites is copyright protected. You should always check if this is the case before accessing the site and retrieving the info. In most cases you will find Terms and Conditions that simply state the information on the site is copyright protected and the information is provided for personal use. In some cases you will find conditions stating it is not allowed to access the site using software. Check and be aware of the position of the owner of the site. In some cases there is a charge on information on a site and sometimes this can be by-passed using programming. Do not kid yourself or anyone else, should you do this it is called stealing and you may call yourself a thief.

It is not because something can be read by the general public that there is no copyright. Copyright is always owned by the creator and remains his/her property unless or until explicitly stated otherwise.

Speaking about Copyright, this course, lessons and assignments, was created by me in the summer of 2004 ( may – july 2004 ) and I hold the Copyright. I provide the course free of charge and to the general public, however I do have the intellectual ownership, at least on the parts I wrote myself of course. You as individual may use the course, both on-line, as well as printed, for your personal use. Any other usage, especially commercial, requires my prior written permission. You may contact me using : datapunter@hotmail.com

Where the course contains references to information on other locations such as Sun Microsystems the Copyright conditions of that intellectual owner is applicable.




Second there is bandwidth and server capacity. When accessing a web site it is always located on a server, being the computer, or computer network, used by the site’s owner to run the site. The capacity of such a server is usually such that it can handle the expected amount of user access in a way a normal service is guaranteed. If you access the server using software you could access it a million times in an hour, much more than any normal user. This will of course put a strain on the server not expected and may cause problems. Be responsible about this. Do not access a site beyond what is required.

Why this piece on responsibility ? Well what you do with the know-how from this course is up to you, I will say no more about it. But as someone teaching about programming I would be negligent if I were not to mention it. The rest is up to you.


10.2 Error handling.

During the course of a program’s execution many errors can, and will, occur. These can be related to the environment like no internet connection, or a full hard-disk. These can also be related to actions inside the program itself like division by zero, or accessing an element of an array that is outside the range of that array. So how do we deal with those occurrences ?

In short, each method in a Java program can throw an error object. This error object can then be caught by a separate block of programming. The advantage is that your code can concentrate on what it is supposed to do, making the readability efficient. It’s not cluttered by a lot of IF error statements. The tutorial by SUN explains the in’s and out’s of error handling quite well, i strongly recommend you go through it completely. you can find it here.

java.sun.com/docs/books/tutorial/essential/exceptions/index.html

If you possess the common sense required to write descent programs you will read the tutorial and apply error handling to an extent that is appropriate for your applications. There really is nothing much I can add to the tutorial.

If you do not possess this common sense and choose to ignore error handling, well, that is fine. The consequence is your applications will be error sensitive. There is nothing more I can teach you on this subject. Its up to you.


10.3 Running programs unattended using timers.

It is possible in Java to use timers to run programs at fixed moments in time or even repeatedly with given time intervals. This is beyond the scope of this course. Given enough interest I may write some bonus lessons on the subject in the autumn of 2004. For now I will simply leave you with the link to the tutorial on timers, or Timer Threads as there called.

java.sun.com/docs/books/tutorial/essential/threads/index.html


10.4 Sending yourself email.

There is the possibility to send emails from inside Java programs. To do this you need to use an external package containing the objects from email handling. You should also know that Java does not have an email server as such. Java uses the existing internet and email connection provided by your internet provider. If you can receive and send email using for example Outlook you will be able to send and receive email in Java. In fact Java simply becomes an email browser just like Outlook. This is especially useful when combined with Timer Threads. Again this is beyond the scope of this course and may become the subject of a bonus lesson.

Here is the link to the tutorial describing the email system.

java.sun.com/products/javamail/



10.5 Where do you go from here ?

Now we come to the end of the course. All that remains is writing the application we set out to write: an Odds Comparison application. At this point it should be clear to you what is involved in writing Java programs and you could be in one of 3 places.

You could come to the conclusion that programming isn’t really something for you.
Well, that’s fine because programming isn’t for everyone. I’d like to thank you for sticking with the course and I hope you’ve learned something along the way.

You could be at a point where you want to continue because you really want the application you set out with, but that’s all you want and you are having a hard time. Well, stick with it. I said when starting this course that I would commit to you being successful, and I stick with that. I never said it would be easy or fast. It is simply going to take the work its going to take.
It’s that simple.

You could be in a place where you absolutely love it. You just can’t get enough. Your mind is overflowing with ideas for applications you just don’t know where to start. Well, welcome to the world of Java programming. Where to start ? Why not start at the beginning. Have a look on the net and in some of the bookstores and get yourself a decent book on Java programming. Go through an entire course for beginners, there are quite a few chapters I left out or only mentioned briefly because of the limited context of this course.



10.6 Final thoughts.

Well, that’s it. JAVA programming in a Sports Betting context in 10 lessons. It has been quite a job writing this course, I’ve learned a lot myself along the way and have enjoyed every minute. I completely bow my head to anyone capable of writing a whole book, what a task.

All that remains is to thank you, the participant, yes I mean YOU, for your confidence, patience and trust in following this course. I hope you found it effective in learning Java and it gets you started to make some nice time saving applications. I would love to hear from you how the course was for you.


Feel free to contact me on the Punters Lounge or at DATAPUNTER@HOTMAIL.COM

All the best,
Erik Bogaert

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Copyright © 2004, Datapunter, (Erik Bogaert)

[Datapunter]

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