Dalton Camargo

Portuguese BLOG

2009-07-11T14:48:00.002-07:00

Hey, if you can read Portuguese, use this link to see my weblog in Portuguese.
I don't have time to update two blogs at the same time :-)

http://daltondecamargo.wordpress.com/

See you.

News of my personal projects

2008-02-07T13:50:00.000-08:00

Hi all, I'm sorry about my delay in subscribing new posts, but i'm really busy in my personal projects and with my life.
Probably nobody knows, but I have two personal projects that I'm taking alone, one of them is: www.empregonaweb.com (emprego means jobs in English), like the name says, this is my Job Portal. The another one is called Infoblogs.com.br, this is about an IT Blogs aggregator, but not only aggretator, infoblogs has a particular database which the users can give "credits" for posts of the bloggers and so forth.
Those two projects are my "hobbie" while I'm not in the Gym or with my girlfriend (and another things), but the truth is that I love to maintain portals!

daltondecamargo at gmail.com

Spring 2: What's New and Why it Matters

2007-01-30T07:54:00.000-08:00

What's New and Why it Matters is an infoQ article by Rod Johnson, the first of two part. This in-depth piece is well worth reading for anybody wishing to understand the evolution of Spring 2.0 as it introduces significant new features, and how these combine to provide the simplicity and power that is the central theme of this release.

JavaBB 0.86 is out!

2006-12-11T05:27:00.000-08:00

Now JavaBB works with Tabs! All categories in JavaBB now are divided by tabs.
While you work, you can let javaBB opened in your firefox tab and when new topics are included, JavaBB will reload (using JavaScript setTimeout) and the new topics are going to be shown to you in the title of your firefox tab, similar as Gmail. Beyond this, was included attachment for post files in JavaBB 0.86 version.

Have a look at the newest features:
http://www.javafree.org/dependencias/javabb/version/javabb86.html

JavaBB 0.85 is available!

2006-10-03T09:13:00.000-07:00

JavaBB 0.85 is available!
Many different features includind ajax implementation has been launched in this version.
Please, if you are using older versions of JavaBB, try this version because many security bugs have been fixed.
If you would like to see javaBB runnig, visit JavaFree.org, the most popular Java community in Portuguese Language.
www.javabb.org

Some projects that are using JavaBB:

http://www.wakeboardingmag.com/forum/forum.jbb
http://www.chailounge.co.uk/lounge/forum.jbb
http://www.mmahellas.gr/forum.jbb
http://www.destinationweddingmag.com/forum/forum.jbb
http://www.sportdiver.com/forum/forum.jbb
http://www.caribbeantravelmag.com/forum/forum.jbb
http://www.egenial.corphost.com.br/javabb/forum.jbb

Have you ever heard about SwingX??

2006-09-04T17:04:00.000-07:00

Of corse you have!
SwingX is a set of components intended to extends functionalities of Swing API default.
Let see how integrate a set of components to the Netbeans' Pallet 5.5 beta, but you can do it from 5.0 version.

To do it, click right button over Pallet and select 'Pallet Manager', make a new category (New Category) that you can call as "SwingX" and add SwingX jar (Add from JAR).
Now we need say wich classes will be added to the Pallet. These classes are:
JXCollapsiblePane , JXComboBox, JXDatePicker, JXDialog, JXEditorPane, JXErrorDialog, JXFindBar, JXFindPanel, JXGlassBox, JXHyperlink, JXImagePanel, JXList, JXLoginPanel, JXMonthView, JXPanel, JXRadioGroup, JXRootPane, JXSearchPanel, JXStatusBar, JXTable, JXTableHeader, JXTaskPane, JXTipOfTheDay, JXTitledPanel, JXTree, LabelProperties

Note: These classes are of SwingX API stable, the development API has some extras components.

After some "nexts", we have the SwingX components integrated with our NetBeans :). You can add these components without problems into of JFrame or JPanel.

Take a look at the Pallet of SwingX into NetBeans!

Thnks Elias :)

Release 0.1 added for Spring Framework Netbeans module

2006-09-04T13:57:00.000-07:00

My partner of JavaFree, Marcos Silva, has written about Netbeans plugin support to Spring Framework.
I haven't already used it, and it seems that is still in development (0.1 version).
Summary:

An early release of a module providing Netbeans integration with the Spring Framework has been released. The module allows users to select select the Spring Framework when creating web applications in Netbeans. The module will then add the necessary libraries, configure spring in the web.xml, and register an XML Catalog in the netbeans runtime tab. This will enable XML code completion when editing Spring Framework beans configuration files.

http://spring-netbeans.sourceforge.net/

Captcha in JavaBB Project

2006-08-14T10:23:00.000-07:00

I have noted that many "fake users" had already inserted in our DataBase. But, how it happened?
Simple! We weren't using Captcha control. Do you know what is Captcha?

From Wikipedia:

A CAPTCHA (an acronym for "completely automated public Turing test to tell computers and humans apart", trademarked by Carnegie Mellon University) is a type of challenge-response test used in computing to determine whether or not the user is human. The term was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper of Carnegie Mellon University, and John Langford of IBM. A common type of CAPTCHA requires that the user type the letters of a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen. Because the test is administered by a computer, in contrast to the standard Turing test that is administered by a human, a CAPTCHA is sometimes described as a reverse Turing test. This term, however, is ambiguous because it could also mean a Turing test in which the participants are both attempting to prove they are the computer.

After this, I've just put Captcha in JavaBB project, as you know, JavaBB is my OpenSource Project based on phpBB project.

JavaBB is a software based on Java, developed specifically with intention to join communities.
Based in phpbb, we are working pledged by the success of phpBB, to become javaBB so efficient as it.

Well, let's straight to some example of how you can use Captcha in your Java Project. In this example, I'm using SimpleCaptcha library. After all, what is SimpleCaptcha??

From SimpleCaptcha site:

The purpose of the simple java captcha project is to make it easy to generate good-looking captchas with a minimum of programming and preferably little configuration.

SimpleCaptcha is an open Source Java implementation for captcha creation. Integration is left to the developers of the individual projects because I don't (want) to know your implementations...

My original interest for the thing was after a distributed dictionary attack against one of our systems. Just to make it a little harder we put a quick hack of a picture on the site. The thing was configured so it would only enable itself when an x amount of logins would have failed over an y amount of time. Unfortunately this was found too confusing.

Put in your web.xml the follow lines:

<servlet>
<servlet-name>Captcha < / servlet-name>
<display-name>Captcha < / display-name>
<servlet-class>nl.captcha.servlet.CaptchaServlet < / servlet-class>

And this mapping:

<servlet-mapping>
<servlet-name>Captcha< / servlet-name>
<url-pattern>/Captcha.jpg< / url-pattern>
servlet-mapping>

Now that you have already configured your web.xml, you must use in your JSP file (velocity, freemarker template and so forth..) an image control like this:

<img src="Captcha.jpg">

and in your Controller (Action of Struts, WebWork..) or in some JSP file, you must check the value from the text field against the captcha key stored in the session:
(String)session.getAttribute(nl.captcha.servlet.Constants.SIMPLE_CAPCHA_SESSION_KEY) ;

Note that with each request to the servlet the current value of the key in the session is replaced with a new one.

The image generated by SimpleCaptcha library

Well, now that you know how SimpleCaptcha works, you can download and try by yourself :)

A little bit about Spring 2.0

2006-08-07T12:16:00.000-07:00

Yesterday I was playing a little bit around with the new features of Spring 2.0.
I would know how Spring Team can think in features that can improve more and more this framework that in my opinion is enough great.
I made some and I’m really surprised the ability to attach post-instantiation processors to beans which have NOT been instantiated by the Spring container. This means a lot to me when I started thinking about how this feature can add value to the current scheme of things in a POJO based Spring configured application.

Let’s straight to example:

public class Product {
// price
// getters and setters
// domain behavior
}

As you know, a typical domain object is instantiated in the application either from the ORM layer -read Hibernate through persistence services- or by the user using factories. Any sort of service injection that is done will be through hardwired code

public class Product {
// ...
public BigDecimal calculatePrice(...) {
BigDecimal productVendorsPrices =
VendorsRateDAO.getInstance().find(...);
// ...
}
// ...
}

The above domain class now has a hardwired dependency on the class VendorsRateDAO, which brings in all sorts of unwanted side-effects :

Domain layer should be persistence agnostic
The domain classes should be unit-testable without the service layer
Proliferation of business logic in the controllers

// Controller class for product entry use case
public class ProductService {
// ...
public void enterProduct(...) {
Product pr = ProductFactory.create(...);
//..
}
// ...
}

Wow, its smell so dirty code!! The domain model becomes anemic !.

Using Spring 2.0

Using the new extension of AOP in Spring 2.0, you can inject any object even if it has been created outside the control of the container.
Spring 2.0 offers annotation driven aspects towards this end as the most recommended approach towards dependency injection into the domain model. Let us see how the Product class changes :

@Configurable("product")
public class Product {
// ...
public BigDecimal calculatePrice (...) {
BigDecimal interest =
dao.find(...);
// ...
}
// ...

// injected DAO
private VendorsRateDao dao;
public void setDao(VendorsRateDao dao) {
this.dao = dao;
}
}

And the usual stuff in the XML for application context :

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 ...>

  <aop:spring-configured/>
  
  <bean id="vendorsRateDAO"
    class="org.javafree.dao.VendorsRateDaoImpl"/>

  <bean id="trade"
    class="org.javafree.model.Product"
    lazy-init="true">
    <property name="dao" ref="vendorsRateDAO" />
  </bean>  
</beans>

Well, now that you know how Spring can lets you Architecture more cleaner, why are you using EJB yet?

RubyOnBr.org borned

2006-07-06T06:00:00.000-07:00

This week borned the first Ruby Community on portuguese language.
RubyOnBr is supported by JavaFree.org, one of the most important Java Virtual Community Of the World. RubyOnBr was created using the same architecture of JavaFree.org, both are in the same server hosted by Prevayler.
Congrats to Ronie Uliana, Adriano Dadario and Vitor Pamplona that spent a lot of time to make reality this community.

Try RubyOnBr

Editado

2006-06-26T10:27:00.000-07:00

Editado

Some pictures of 4th Day

2006-04-23T05:46:00.000-07:00

Me showing our site

"Carolina, this is my friend Tux".
"Hi tux, Dalton talks a lot about you, nice to meet you." hehe
Carolina is my Girlfriend!

Me and Marcelo Tosatti. Marcelo is a linux kernel 2.4.x maintainership

3rd and 4th Day

2006-04-22T07:43:00.000-07:00

Here we have a lot of other picutures :)
http://www.javafree.org/javabb/viewtopic.jbb?...

Enjoy!

7th Brazil's free software forum!

2006-04-20T16:44:00.000-07:00

The FISL (Forum Internacional do Software Livre "In Portuguese") stay rules a lot!! Our community are there and we are having fun :)
Above some pictures of the event:

This guy with the blue shirt came to our stand and asked "Please, don`t fight with me, I`m a phyton developer, but I wanna know something about java" LOL

The other guys:
Vitor Pamplona, Dalton Camargo, Phyton Developer and Elias.

Here we are showing our new banner.
Thanks to Ciencia Moderna that help us to buy it.
Roni Warken with Red Shirt and me

Here I`m showing my Best Seller (LOL), Spring in Action in Portuguese :)

Some important peoples have been there:
In the center of this picture is Klaus Wuestefel, the creator of Prevayler, Byecycle and other great projects. Klaus is the Director of Objective Solutions, this company helps our community paying a dedicated server.
Thanks a lot Klaus!

I`m here :)

Click here to see other pictures of FISL.

JavaBB 0.80 is available

2006-04-07T15:40:00.000-07:00

I'm pleased to announce that JavaBB 0.80 is available!
Try it !

We have a lot of changes in this version! The security control has been changed and many features had been included.

JavaBB.org is a software based on Java, developed specifically with intention to join communities.
Based in phpbb, we are working pledged by the success of phpBB, to become javaBB so efficient as it.

Try it!
www.javabb.org

If you are using JavaBB in some project, let me know in comments.

Thanks a lot

Dalton Camargo
JavaBB Owner