I arrived home this Tuesday and I'm still recovering from the travel, but I can assure you J1 was great!!!

In the next few days I will write more about how the conference was, I still need to get some pictures with friends.

[Time for thinking...]

Yeah, that's true! This is not an april 1st joke :)

We have been working for the last month in new features in marge-core, the framework itself, and also in a new version of Bluechat. Now, we happily present marge-core v0.5, with the following diffs from 0.4.0:

• Created AutoConnect class to make directly connections; (That's very cool! You can connect two bluetooth devices with just one line of code!);
• Created the concept of layer (Currently there is beta unicast layer. Feel free to send new layers or tips for the layers mechanism);
• Created UUIDGenerator that receives a name and automatically generates a UUID following the given name;
• Created more methods in Inquiry/Discover to make this stuff easier, removing the JSR 82 int constants;
• Coded small TODOs and XXXs (hashmap for server configuration, new default service, etc);
• Moved project to NetBeans (see more about that above);
• Organized the Subversion repository to make it more comprehensible.

The project was migrated to NetBeans 6.0, because we believe that, at the moment, Mobility Pack is a much better tool for Java ME development than the available free solutions for Eclipse. Anyway, you can see that we don't want to force anybody to use it, cause you can still use the available Ant scripts provided by NetBeans or import the source directly.

Also, more than a new release, today Marge is completing 1 year since our first commit to the project repository, which means Marge is doing his first birthday!

We want to thank you all that have supported, tried, gave feedback and worked with the project during this time. We know that the project wouldn't go on without your help and because of that we are thankful. Now, we expect that you that already use Marge, keep using and sending your ideas, and for that ones that have never used Marge, this is the perfect chance, cause the project is getting better every new release!

Thanks again and don't forget to go to the project's web page, take a look in the new features and give a try!

In the end of last year, I saw some slides from a presentation about ZFS from Sun, using a bunch of memory sticks to create a file system, and thought that very cool. Today, I found an article called "Playing with ZFS, USB memory disks and VMware Fusion" and decided to try it myself, but in a different way, using VirtualBox instead of VMware.

First of all, I installed VirtualBox in Ubuntu Linux. After enabling the respective repository, just did an "sudo apt-get install virtualbox-ose" and added my user to the "vboxusers" group. Then created a virtual machine for a Solaris installation and installed the preview 2 of project Indiana. I was having problems to install Indiana every time I gave information for creating a new user, but when I gave just root password everything went fine.

For this test, I got two pendrives: one with 1Gb from PQI and a USB memory card adapter from Nokia, with a 512Mb mini SD card. VirtualBox was presenting some problems to use USB devices, but after some googling I found the solution here (Portuguese) and here.

With VirtualBox working, was time to create my first ZFS pool.

With the command "rmformat", I discovered that the two memory sticks were the devices "/dev/rdsk/c9t0d0p0" and "/dev/rdsk/c10t0d0p0". Therefore, created the pool with command "zpool create -f usbdisk c9t0d0p0 c10t0d0p0".

Now, with "df -h", there was a new file system called "usbdisk" with 1.4GB (the adition of the two memory sticks :).

But I was curious to see if it was really working, so I created a new file in "/usbdisk" with 1200Mb (bigger than the bigger memory stick capacity), and there it was:

Rebooted the system to check it was really true, and the file still was there. That's Great! Fantastic for projects like to create "A Home Fileserver using ZFS".

But after closing the virtual machine and openning it again the file wasn't there anymore. This got me upset, but just for a few seconds before I saw that still there was something in the pool, using "zpool list".

Then executing "zpool export usbdisk" and "zpool import usbdisk" all got back again. Must be something related with the usb devices, but now I know there is no problem removing the devices or even mixing them.

There are alot of features available in ZFS, like creating file system with RAID redundace, use the available GUI and many more. Here are some additional information:

* Solaris Operating System - ZFS Learning Center
* BigAdmin Feature Article: ZFS Overview and Guide

First, to get prepared for the exam, I started reading some material about it's content that I found at the Internet. For example:

http://www.scja.de/index.html
http://ejavaguru.com/scjafreemockexam.php
http://www.whizlabs.com/articles/scja-article.html
http://cafe4java.com/mockexams/scja/mock1/q1.php
http://www.javacertificate.net/interview_qns.htm

Every Sun Campus Ambassadors has the possibility of earn free vouchers for Sun Certifications and pay nothing to take the exams. The only requisite is to do a test at Learning Connection (http://learningconnection.sun.com)*¹ and pass it. So, after I did the exercises at the websites I mentioned, I went to Learning Connection and took a test exam called "Sun Certified Associate for the Java Platform, Standard Edition, Exam Version 1.0 (WGS-PREX-J019C)". In this test, you have to do 4 exams with 51 questions each, covering the content necessary for SCJA and you have to answer correctly at least 35 of this questions in each exam. Done that, I requested my free voucher.

Then, I went to Prometric website, created an account, chose the date and one available center in my city, Florianópolis. That's it, I just had to wait a few days and come to the appointment.

So, yesterday, like I told before, I went to SENAC, here in Florianópolis to took the exam. The appointment was at 6h pm, but I arrived at 4h30 pm. Please, don't do that, cause you will have to sit and wait :P. When was time, I was asked for two documents with signature and photo. I presented my drivers license and my passport. After that, I was conducted to a tiny room (2x1 meters, I think), where there is only a computer inside e two vigilance cameras (I think it's not a good idea try cheating :).

You sit and start the exam process. First, I had to answer a little survey about the knowledge level I believe I have (basic, advanced, etc). Then, the real exam starts, but you don't really have to be scared, cause the exam questions looks pretty much like the questions that are available in Internet and Learning Connection about SCJA. Also, there are plenty time to answer the 51 questions, a little less than two hours.

In the beginning, I stayed a little nervous. Answered the first, the second... (now you start to see there is no mystery at all), end in the 51th. You can now check your answers. It's everything OK? You finish the exam and a message appears telling that your result is in the registry room. this is the tense moment, where you leave the room and have to go back and check how well you did. When you arrive there, the Secretary will give you a mysterious look, just to try get you nervous :P. Don't worry, in few moments she will show your results and you will realize that everything was all right.

I passed with 96%! Even the security guy gave me a smile =)

This text was all about showing you that there is no complication in taking a Certification, only benefits. For example: now, I'm sure that my Curriculum looks better. I think I spent about 6 hours studying. I just payed attention at the exercises and every time I missed a question I tried to understand why I was wrong.

Now, good luck to you! I will start to study to SCJP...

*¹ Learning Connection has several courses about Sun Technologies. To be able to access it, your University should be part of Sun Academic Initiative.

--
;)

Lucas B. Torri
[00:12:62:F8:E1:0C]

So, for everybody that can read Portuguese (or is interested in learn :), visit http://www.gujavasc.org.br

Roger Meike, research director at Sun Labs, said: "We created this technology to inspire students and educators to develop new, creative and useful applications". Also, he says that the decision of open sourcing the SPOT libs are based in the commitment to support the growing community of developers.

These are great news for we, SPOT lovers, and the Open Source community. Thanks!

The package from Sun

T-shirt front, that remember a metro map

T-shirt back, with NetBeans logo

It looks even prettier than the normal labels:

Like the designer says "I find it surprising 70% of people don’t read the care labels and when they do, it’s usually too late". I personally don't know anything about cloth labels, so this would be a great help to avoiding me to destroy clothes =P

Notice found at Make Blog

Last month I got a Sun SPOT from a friend that came back from US and I can say that the kit is very cool. Now, in my way to learn more about it I decided to add a Humidity Sensor to the board.

This was my first experience on extending the SPOT hardware so in the beginning I was a little petrified but the process showed to be very simple. I got a free sample Humidity Sensor from Sensirion . I didn't imagined it was so little.

After wiring up the sensor and adding the necessaries resistor and capacitor I powered it, but there was no way to know if it was working, so I started to implement the Sensor communication protocol using Java. The component has 4 connectors: VDD, for power supply; GND for ground; DATA , for bidirectional data transfer and for last SCK that is clock signal for controlling the transfer. I decided to use +3V and GND available in the SPOT board and D0 e D1 for SCK and DATA respectively. The result program you can download here. This program is responsible for achieving the Sensor data and convert it using the formulas given by Sensirion.

Then, I connect the wires of the Sensor circuit to the SPOT board, programmed the software and surprisingly I got the expected results, showing that current temperature is near 29 Celsius degrees and the relative humidity is in 79%. SOrh and SOt are the values got directly from the Sensor.

All this got me less than 2 hours. Using the Sensor Data Sheet and SPOT Javadoc and documentation as reference I can say that this task was incredibly easy to do.

The Solaris installation was really simple, just inserted the cd and followed the steps. The Workstation has two Ethernet interfaces, that are called in the system as nge0 (Gigabit) and nge1. We have chosen to use nge1 to connect to external network and nge0 to create internal network for the Sun Rays.

After configured the nge1 through the Solaris wizard, we have installed the Sun Ray Server with the cd that comes with the Workstation. Just run a few commands and followed the steps on then (in the respective order: "/cdrom/cdrom0/utinstall", "utadm -a nge0" and "utconfig") and there it is, a set of Sun Ray Clients working using just one machine.

The workstation and a Client:

Some of the other Clients:

Sun Rays are great! I invite you all to take a better look and see more details here: http://www.sun.com/software/index.jsp?cat=Desktop&tab=3&subcat=Sun%20Ray%20Clients

A few days ago, Sun announced that is going to sponsor Open Source community with $1M. In my opinion this is a great way to encourage students to get involved with Open Source projects.

One of the sponsored projects is community for researches related to operating systems, called OpenSolaris. The list and wiki for the OpenSolaris Community Innovation Awards are now open. If you'd like to get involved, please go here:

http://www.genunix.org/wiki/index.php/OpenSolaris_Community_Innovation_Awards

Today I got surprised when a big box come in my house. It is a Ambassador kit with cds (with NetBeans, Sun Studio and others), OpenSolaris books, T-Shirts, pens, a backpack and many more.

I just got crazy, started to open the box and remove everything from inside:

The Ambassador T-Shirt, backpack and pens:

CDs and OpenSolaris keyfobs:

December 20th I'm going to São Paulo, Brazil, to meet the Ambassadors from the rest of the Country and Gary Serda, that also will be there. That's really exciting!

pt:
Estamos aqui em São Paulo, Brasil, no JustJava 2007 (http://www.sucesusp.org.br/eventos2007/justjava07/), evento do SouJava. A foto acima mostra o Mauricio Leal (http://weblogs.java.net/blog/maltron/) fazendo a abertura do evento.

Hoje a tarde o Neto Marin (http://weblogs.java.net/blog/netomarin) vai apresentar um tutorial sobre Java ME (parte I e II) e amanhã teremos uma trilha sobre Java ME, com vários assuntos muito interessantes. Então fiquem ligados nas próximas notícias!
---

en:
We are here in São Paulo, Brazil, in JustJava 2007 (http://www.sucesusp.org.br/eventos2007/justjava07/), an event by SouJava. The photo above shows Mauricio Leal (http://weblogs.java.net/blog/maltron/) openning the event.

This afternoon Neto Marin (http://weblogs.java.net/blog/netomarin) will present a Java ME tutorial (part I and II) and tomorrow we will have a Java ME track, with a lot of interesting subjects. So stay tunned for more news!
---

;)
Lucas Torri

In this vast world of available scripting languages, one that really calls attention is Jython[http://www.jython.org]. Jython, is the Java implementation for the high-level Python language, allowing you to run Python on any Java platform.

Python is a multi paradigm language, can be learned in a few days and used to write any kind of application. Also, many programmers report substantial productivity gains using it.

The syntax is a little bit different from usual languages, cause uses indentation to separate blocks of code, which makes Python a highly readable language. An increase in indentation comes after certain statements and a decrease in indentation signifies the end of the current block.

For me, the biggest advantage of using Jython is that it provides interactivity with Java Classes and Objects. This property, makes possible, together with the interactive, interact with Java resources, allowing programmers to experiment and debug any Java system using Jython.

Installation is made through a GUI installer, making this process very simple. After that, you can run the Jython interpreter running the executable file in the installation folder. Once the intrepeter it's open, you can starting coding like in every other editor, but in each new line the code will be instantly interpreted. For example, look how easily I create a JFrame using Jython:

>>> from javax.swing import JFrame # import the JFrame class
>>> j = JFrame(title='hello world!', size=(400,100)) # create a new JFrame instance and automatically sets title and size
>>> j.visible = 1 # the same as j.setVisible(1)

Notice that the 'new' ain't needed and you can access and modify attributes without get/set before. Also, integers can be used as booleans, but there are also available the True and False operators. The line setting the frame visible could also be inside the constructor, making the code even smaller.

It can be used to write automation scripts, including ones that use JDBC, use it as a script language inside your programs using the project jar or even use Jython compiler (jythonc) to transform the python code to Java code. All this using a very easy and high-level language.

I'm not trying to write a Jython tutorial here, this is just to give you a little taste. So, if you want more information about that, I recommend you to check this:

* http://www.jython.org/Project/index.html
* http://www.oreilly.com/catalog/jythoness/chapter/ch01.html
* http://www.onjava.com/pub/a/onjava/2002/03/27/jython.html