R E P O R T

Conception
This time the conception was really easy... I had to take an old exercise and redo it with Java. So, I decided to take the quiz I have done for exercise 2 of STAF14 with PHP. The theme was "Transition period of Euro". Why this exercise? But of course, because it was a server-side application. So, the philosophy was pretty close or at least that's what I thought...

I was quite releaved that I didn't have to think about the subject of this quiz and at the same time, I was excited as there was already a challenge (I always need this in order to start doing something :) The old exercise had an innovative characteristic, questions one by one in successive pages and immediate feedback after each answer. Doing it again, this time with a Java servlet, seemed very interesting as I found really easy to do a classic quiz with a Java servlet.

So, my Java servlet has the same "look" with the old exercise and maybe someone won't even be able to distinguish which is which, but I definately can, because I had to get into the java servlets documentation and more precise to study "session tracking".

I borrowed the code of an example for a Shopping Cart and I was really excited to see how session tracking is being done with "cookies", something that I have watched several times in the e-commerce but I didn't know how this is being done...

The scenario

Introduction page:

At the beginning, the user faces a "welcome" page and starts a session by giving his/hers name and by accepting a "cookie".

Question mode:

Each question is being presented the same way with the old exercise, one by one in a page and the user has to choose from 3 radio buttons the correct answer and verify his answer by submitting it.

Feedback mode:

The verification of each asnwer is being done immediately by reminding the question and the possible answers plus a feedback message. Only that the possible answers this time have an icon in front, either a green "tick" before the correct answer, either a red "cross" before the wrong answer of the user (if there is one).

Results:

After answering to all of the 10 questions of the quiz, the user can watch his score and a feedback concerning his knowledge on the subject. There are of course the links to go and take a look to improve his knowledge or decide to redo the quiz ...

Technical details - problems
Doing a simple quiz with all the questions in one page was quite easy with a servlet so, by just watching an example I was able to do my own test quiz immediately after Daniel's presentation. The problem started when I decided to do the successive pages that meant session tracking which meant going over the documentation... Having not so much free time like last year, I had to be quick and efficient :)

I have to admit that the usefulness of both "doGet" and "doPost" in the same servlet is not so clear to me still. But on the other side, I started to have the feeling of a servlet and understand how it works (at least roughly :) after finishing this exercise.

The things that deserve to be mentioned specificaly:

• session tracking: it's being done with a "cookie" that keeps the session ID.
• succesive pages: created by storing as variables the username, the question number, the mode (feedback or question) and the score.
• educative compliant: proper immediate and final feedback.

References - Bibliography - Sites

• TECFA's Java Resources (especially for servlets)
• Java Web Server API (including javax.servlet)
• Stefan Zeiger's Tutorial for servlets
• Shopping Cart code
• "Java Gently" by Judy M. Bishop,ADDISON WESLEY, ISBN 0-201-59399-8
• "Java in a Nutshell" by D.Flanagan et al., O'Reily, ISBN 1-56592-304-9
• "Java examples in a nutshell" by D.Flanagan, O'Reily, ISBN 1-56592-371-5