Felipe Gaucho's Blog

February 2006 Archives

Using OpenSource projects as classroom material

In the last CEJUG - Café com Tapioca, I introduced Cejug-Classifieds as a project designed to be a study-case for the J2EE community. The aim of the project is to allow university students to test their subjects on an alive project, taking advantage of collaborative effort in a real J2EE test bed. The reduced scope and some didactical strategies serve as guidance to students and are also a way for teachers to follow up their pupils learning. Some of these strategies are enumerated below:

Strategies used to facilitate the adoption of the project as classroom material

• The project is an implementation of the chapter 6 of the book Core J2EE Patterns. The book can be used as a guide for the understanding of the code. Every pattern proposed at chapter 6 has an implementation into the project, and students can learn with patterns in action. The correctness of the implementations, the way patterns interact among the others and the J2EE details seem a good starting point for lectures and class debates.
• The classes receive a suffix identifying their patterns, for example: the source of a helper class is named ClassnameHelper.java.
• The package names also receive a suffix identifying their patterns, i.e., the pattern adopted by the classes that composes the package.
• This suffix strategy promotes the following project tree:

  .
  JavaSource
  i18n
  net.java.dev.cejug.classifieds.bean
  net.java.dev.cejug.classifieds.command
  net.java.dev.cejug.classifieds.controller
  net.java.dev.cejug.classifieds.dao
  net.java.dev.cejug.classifieds.filter
  net.java.dev.cejug.classifieds.helper
  net.java.dev.cejug.classifieds.security.jaas
  net.java.dev.cejug.classifieds.security.jce
  net.java.dev.cejug.classifieds.taglib
  net.java.dev.cejug.classifieds.timer.task
  net.java.dev.cejug.classifieds.util
  .

The subjects explored in the current release

Despite every J2EE technique can be explored in the Cejug-Classifieds, some of the classical patterns and web application features were already discussed and implemented by the project members. The available code includes:

Message for teachers

Dear teacher, just as you are, I'm a teacher of undergratuate courses of computing and I share your anxiety about how better to teach and how to provide powerful learning stuff to the students. My frequent search for useful tools in teaching requires innovative thinking, such as the one I described above. Some ways you can use the Cejug-Classifieds in your classroom:

• Just download the project contents from CVS and evaluate it with your students
• Ask for a CVS branch in order to keep your own version of the classifieds. The enhancements you do in these branch can eventually be merged into the project head.
• Ask for a subproject or a separate study project inspired on the classifieds, perhaps with a formal link between the projects with a guidance from the java.net community leader.
• Ask me for an isolate folder inside the project, where you and your students can create a new flavor of the project
• Your idea here - the main goal of the project is to become a good tool for teaching and every idea about how to reach that will be considered.

If you agree with the idea of an Open Source project designed to be used into classrooms, please help to improve this idea and also give some clue about how my project could help your students. Let's share teachers experiences. Just send me your thoughts about the model of Cejug-Classifieds as learning tool or comment any other trick you have adopted in your university.

Message for students

You are always welcome to learn from java.net projects. If you have new ideas on how such didactical project could evolve to become a good experience, be my guest to post your point of view. Students are the target audience of the project and your sincere opinion is one of most important quality indicator of our project.

Next steps

A complete description of the project and its design is a subject for a further article, but the above brief introduction of its goals cam help you to join our efforts.The next steps are formalizing a documentation about the usage of Open Source projects as didactical tools and also evolving the ideas with your contribution.

The enigma of the T-shirt

During my presentation on the Café com Tapioca, we distributed free t-shirts about the event. On the front side of the T-shirts, you can observe an enigmatic set of letters representing a secret sentence. The first person who reveals the secret message will receive a gift. Just a tip: all you need to decipher the enigma is on the T-shirt and/or into the project code. The t-shirt photos and the enigma are below:

ERRATA: unfortunately the t-shirt was printed with some wrong character, and unfortunately I don't have more the original. Sorry by the inconvenience. In order to keep the competition, I'm posting the new set of (tested) characters: ruRQ3oY91/UdghBSLuzbrkBk/v7k/w2VV9fUwlGMhOf195kgvXh6aTZkbH3H5wZh+GdewgnB4xYvv1SljdckdjcHWfxY LLbUqMmHVle7nu2AgehG4pHZ/Z3uW/J0NgbjdcZuE6jf/tHUPaMkiNIlzXgtqSkLhlpzN/9nSggDVSu+EHBW+bvW8w==

Good luck ;) all photos of the event and the presentation in Brazilian Portuguese are here.

The IDEs are driving us crazy

Planet Earth, 2006 A.D.
Workstation: java.net
Module: Cejug-Classifieds
Status: active

If you had patient to observe the above report, you noticed some messy running on the code produced by the project team during february. The scenario is simple:

Seems familiar ? I guess so because almost every project I ever seen in my life suffers from configuration problems. If you are a member of a project in which every person could choose his own development environment, I'm sure you have painfull experiences with the code-style, integration and even the project communication. It is so common I decided to register this situation here in my blog.

Two other recent situations I experienced in my projects:

1. The project I'm working uses a modified template where the Line Wrapper was modified to 255 columns, instead of the traditional 80 columns. One week of good job and I decided to update my IDE - I installed the new version in my computer and keep working on the code. Few days later a colleague asked me: did you change the Line Wrapping rule?. Of course, as human being, I was tired and also excited with the new version of my IDE - and I simply forgot to redefine its defaults before start working.
2. A member of my Open Source project decided to contribute - he updated the CVS snapshot and fixed several open issues. Great job, unless a mute trap - the IDE he was using adopted the file encoding of his operational system, completely different from the project defaults. Nowadays, the project has part of its code in UTF-8 and part of it in Cp1252.

Machines: please don't think, just obey

The configuration problems seem ontological to computing and I can't imagine great solutions without much human interference. Despite that, several IDE vendors are designing heuristics to provide their IDEs the ability to guess what the humans are trying to do. This comfortable feature causes lazyness and ignorance about the development details - such as file encoding or code-style, for example. When a machine start taking decisions instead to ask the person what to do, the problems start. I think friendly IDEs as a great stuff, but it should be less pretentious about their ability to help us in our duties.

Some ideas: project descriptors like the ones used by Maven seem a great idea and something like that could be available for the IDEs. Imagine for a minute a specification of a XML Schema created by a consortium of IDE providers, in order to unify the project descriptors. Imagine now that every IDE forces the user to inform this default project descriptor in order to start a new project. Wonderful ? I guess so. Unfortunately, it seems far beyond the reality. For now, all responsability to reconfigure every new tools is still on humans and, you know, humans are not perfect.

Until we can figure out a solution for configuration problems, I enumerated a sanity checklist to help you to keep your team working together - if you know smart ways to avoid configuration problems, please let us to know.

Tricks to keep the team sanity:

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