http://www.dalouche.com/wordpress Sami Dalouche's blog about Linux, Java, .NET and other bleeding-edge stuff. skoobi@free.fr Fri, 27 Jun 2008 23:42:26 +0000 http://backend.userland.com/rss092 en A Validation Framework Consolidation JSR was started last year. Like others, I appreciate the initiative, but given that there's not much activity around this JSR, are we going to see some consolidation in this area anytime soon ? Anyways, just a note explaining why I think it IS a good idea ... http://www.dalouche.com/wordpress/2007/06/02/validation-framework-consolidation-where-are-we/ Just a few words to give my opinion about this post on Acegi and AppFuse 2.0. ACEGI 1. If you use composition, your domain objects don't have to implement the UserDetails interface, so you don't have to "pollute" them. 1'. Even if you do not use composition, implementing an interface doesn't  mean your ... http://www.dalouche.com/wordpress/2007/04/17/acegi-and-appfuse-20-captcha/ I happened to read this blog entry about NOT reinventing the wheel. I 100% agree with the author. However, I would like to add something important : Reinventing the wheel is bad, but integrating too much stuff together will necessarily cause headaches about version incompatibilities, subtle problems, etc.. For instance... Let's ... http://www.dalouche.com/wordpress/2007/03/03/re-inventing-the-wheel-vs-integrating-many-libraries/ I came accross this blog entry which is a mini "howto install maven2 under debian". Thanks for the hint, and thanks to the Debian Java team for working on official Debian packages for maven2. However, I think we have a deeper problem than just the lack of maven2 package..  Just take ... http://www.dalouche.com/wordpress/2007/03/03/maven2-for-debian/ Let's say you want to display a Dojo ProgressBar, that has a max progressValue of 10 : Now, you want to animate it so that it progressively reaches its progressValue. Something like the following will be needed : function animateProgressBar(progressBarName, targetValue anim) { dojo.event.connect( anim, "onAnimate", function(e) { var bar = dojo.widget.byId(progressBarName); bar.setProgressValue(targetValue * e.x / 100); } ); } dojo.addOnLoad( function() { var ... http://www.dalouche.com/wordpress/2007/02/28/dojo-how-to-animate-a-progressbar/ In a recent post, Ian lists the current limitations of Xen 3.0. Nice work ! Definitely Useful, but I would just like to add that there is a trick that I previously described, to circumvent the 3 network interfaces limit. http://www.dalouche.com/wordpress/2007/01/19/xen-30-limitations/ Here is a funny, satirical comment from Daniel Spiewak on Java code produced by different people (student, professor, developer...). We can probably draw a parallel with the funny quotes about Java I previously cited. My opinion is that every Java developer is aware that everything he does is far more complex ... http://www.dalouche.com/wordpress/2006/12/16/java-from-different-viewpoints/ Sun just announced J2SE 6 and many java bloggers are relaying the information.. Something important for the web development community in this release is the  support for scripting languages. In fact, the trend, that has been started with Java Hotswap, is to create tools that allow Web Frameworks to be more ... http://www.dalouche.com/wordpress/2006/12/11/j2se-6-will-web-development-finally-be-productive-thanks-to-scripting/ Jonathan Locke wrote a post about Meta Patterns. I don't exactly understand what he means by using the "Meta Pattern" expression, but this definitely looks exciting. In any case, I am curious to see one or two examples of these Meta Patterns to truly understand his thoughts. http://www.dalouche.com/wordpress/2006/12/11/meta-patterns/ An interesting post about HTML, CSS is available here. It's definitely worth reading it. http://www.dalouche.com/wordpress/2006/12/11/building-modern-web-applications/ Glen has a short tutorial on how to perform validation using Spring Valang (which is part of Spring Modules, which provide additional modules to integrate external projects with Spring, like OSCache, etc..) . While it is certainly better practice to choose XML validation instead of writing Validator classes manually, I ... http://www.dalouche.com/wordpress/2006/12/10/validation-in-a-web-application/ Jurgen - whom I totally agree with - has written a very nice post about Procedural-Object programmers. Most people tend to forget that Designing/Coding a piece of software is not about getting things to work, but more importantly, about getting things to work in an elegant way. And the biggest problem is ... http://www.dalouche.com/wordpress/2006/12/09/design-patterns-and-the-art-of-software-design/ No matter who you are (Lambda internet/network user, Software Developer or System Administrator..), you are most-likely affected by the proliferation of accounts and passwords. The problem As an Internet user, you need to keep track of one account/password pair for each website you use. It is then necessary to choose between ... http://www.dalouche.com/wordpress/2006/12/09/lets-stop-the-accountpassword-proliferation-mess/ Java HotSwap support is being improved with each release. More information about it can be found in Jonas Bonér and Geert Bevin posts. The goal of hot swapping is to allow the JVM to take new versions of the classes into considerations without reloading the JVM/Application. Jonas believes it is a bad ... http://www.dalouche.com/wordpress/2006/12/06/java-hotswapping-support-and-developer-productivity/ With globalization, Character Set problems are becoming more and more frequent, and are sometimes even a headache, as Mark Pilgrim and Scott Balmos highlight it in their respective posts entitled Determining the Character encoding of a feed and String encodings - another thorn in interop. Character sets are no more ... http://www.dalouche.com/wordpress/2006/12/06/character-sets-issues-and-guidelines/ Dalibor Topic has been interviewed (post here) concerning the recent announcement of Sun to make Java GPL, its implication on the Kaffe project. As far as I am concerned, I strongly believe that Open Sourcing Java will open the door to more innovation and wider adoption around/of this technology. When ... http://www.dalouche.com/wordpress/2006/11/28/interview-concerning-gpl-java/ DWR is an Open Source Java library that allows to write AJAX-enabled Web Sites. Since the "AJAX" term is used to to describe pretty much anything from rich Web User Interfaces to auto-completing combo boxes to asynchronous communication between the web client and the server, here is a ... http://www.dalouche.com/wordpress/2006/11/27/howto-use-direct-web-remoting-dwr-with-spring-framework-and-java5-annotations/ Debian/Ubuntu sympa packages rely on apache1, so one may have problems running sympa on Ubuntu Edgy, for instance. This simple HOWTO explains how to configure Sympa and WWS to run with Apache2 and FastCGI. FastCGI is used instead of CGI because of the performance impact it has. (Basically, CGI forks a ... http://www.dalouche.com/wordpress/2006/11/26/howto-setup-sympa-wws-with-apache2fastcgi-on-debianubuntu-edgy/ Prerequisite : You have Xen running correctly for less than 3 virtual interfaces. This HOWTO explains how to get it to work on Ubuntu Edgy. Xen does not support using more than 3 virtual interfaces on the guest machines (the so-called DomU). It is stated in the Xen FAQ, ... http://www.dalouche.com/wordpress/2006/11/26/howto-use-more-than-3-virtual-interfaces-with-xen-by-using-ip-aliasing/ If you have recently migrated your AWstats to a different Architecture (Pentium4 to AMD64, for instance), awstats may report you the following error : Warning: Error while retrieving hashfile: Byte order is not compatible at ../../lib/Storable.pm (autosplit into ../../lib/auto/Storable/_retrieve.al) line 331, at (eval 8) line 1 This is caused by the fact ... http://www.dalouche.com/wordpress/2006/11/22/awstats-libperl-storage-and-endianness-byte-order-issues/ Here is a simple HOWTO explaining how to configure AWstats to analyze Apache2 logs, and provide detailed statistics, under Ubuntu Edgy Eft. This should also work for other Ubuntu versions, as well as any Debian derivative. Apache The first step is to activate Logging in Apache, so that Awstats has something to ... http://www.dalouche.com/wordpress/2006/11/22/howto-apache2-awstats-setup-on-debianubuntu-edgy-eft/ Most developers now agree they should avoid heavyweight frameworks like EJB2. Maintenance is a nightmare, and more importantly, developers don't enjoy anything that deals with the generation of stubs and skels (The same applies to technologies like CORBA). So, what is the recommended technology stack for developing web applications today ? ... http://www.dalouche.com/wordpress/2006/11/18/the-typical-bleeding-edge-web-application-architecture/ Xen is definitely a great piece of software. It is currently the only viable (truly) Open Source solution to build secure virtual systems by isolating software in their own sandbox, and being able to set CPU/Memory restrictions on each of the sub systems. However, each subsystem has to be managed and ... http://www.dalouche.com/wordpress/2006/11/18/xen-and-selinux-anything-in-common/ OK, so you just bought that wonderful 4U server, with dual-core Xeon/Core 2 Duo, redundant gigabit ethernet connections, redundant power supplies, KVM over IP / IPMI management card, and most importantly, this wonderful fully hardware-based RAID controller (Semi-Soft RAID has been a disaster for me, by the way). Now, the question ... http://www.dalouche.com/wordpress/2006/11/17/raid-5-vs-raid-50-informal-comparisonbenchmark/ The  Can Java CMS match PHP ones article contains a funny, yet sadly true, sentence : Maybe while the Java world was engaged in talking of high end, super techie stuff, with the words 'enterprise', 'transactions' and 'SOA 'embedded in every sentence, the PHP guys actually went out and created a ... http://www.dalouche.com/wordpress/2006/11/04/funny-quote-java-vs-php/ Every web application needs to load initial data into its production database (settings and domain specific data such as available categories, etc..). Another concern is the migration of current data to the new schema. Hibernate/JPA makes it easy to create additional fields, but as soon as data migration is needed, it ... http://www.dalouche.com/wordpress/2006/06/18/designing-java-migration-scripts-for-sqlhibernatejava-persistence-api-data/ Daniel provides a comparison of AJAX frameworks . It is especially useful these days since everyone is starting to develop his own AJAX framework. Not all frameworks are presented (reasons explained), but it's a good start. Keep up the good work ! http://www.dalouche.com/wordpress/2006/02/27/ajax-frameworks-comparison/ This very nice article from IBM gives some information about Aspect-Oriented Programming (AOP), and why it is good for programmers. The author clears the myths and understanding about AOP. http://www.dalouche.com/wordpress/2006/02/15/aspect-oriented-programming/ Basic Integration of Db4o with Spring.NET is now done. Nothing has been tested yet, but testing should soon start... I have created a JIRA issue for this. I hope that this will get integrated and reviewed into Spring.NET. Content of the issue : It would be nice to have Spring.NET integrated with db4o. I ... http://www.dalouche.com/wordpress/2006/02/12/basic-db4o-integration-with-springnet/ After having spent several more hours on the Db4o/Spring.NET integration issue, here are some of my conclusions concerning Spring.NET internals : Most of the logic for integrating a Data Access/Transaction support technology to Spring.NET is to be implemented inside 3 major entities : The PlatformTransactionManager (Db4oPlatformTransationManager) : definitely the main entity on ... http://www.dalouche.com/wordpress/2006/02/10/more-details-about-integrating-db4o-with-springnet/ As previously stated, I am currently working on Spring.NET and db4o Integration. This thread deals with some of my questions regarding what's currently available in db4o that will allow me to do the job. Here's the likely roadmap : Create an equivalent of the JDBC "Datasource" : a Factory that allows to ... http://www.dalouche.com/wordpress/2006/02/09/springnet-and-db4o-integration/ This email from Novell is particularly interesting to read. I believe that they got it right : if you want things to go forward, you sometimes have to create something even though some people won't like it  sometimes. It is especially true for Novell, since they are trying to push the .NET ... http://www.dalouche.com/wordpress/2006/02/08/is-architecturing-the-task-of-one-person-not-a-community/ Compared to its Java peer, Spring.NET's transaction support is still in its infancy and somewhat undocumented. According to some posts in the forum, Transaction support should come with version 1.1 (currently in CVS). In the meantime, those of us who have to deal with transactions still have to find a solution.. ... http://www.dalouche.com/wordpress/2006/02/07/adding-db4o-oo-database-support-for-springnet-transactions/ Thanks to Novell !! See this announcement from Miguel de Icaza or this one from Alexandre Gomes for Xgl and the new compositing manager .. I am looking forward to having everything working on my Ubuntu box... And having applications (f-spot, etc...) using this technology intensively. So now, what does the Graphical ... http://www.dalouche.com/wordpress/2006/02/07/linux-finally-on-the-desktop-thanks-to-opengl/ This particularly interesting post shows how good Spring is : 70% reduction of code after EJB to Spring migration.. I guess Erik is talking about EJB 2, but it's still very interesting ! http://www.dalouche.com/wordpress/2006/02/07/lightweight-spring-container-vs-ejb/ This Topic [Fr] explains photography basics. It is really well done, so it's worth taking a look at it. http://www.dalouche.com/wordpress/2006/02/07/photography-basics/ You can find a nice comparison of DNS Registrars here. All features that matter are compared, thanks to Daniel M. Hendricks ! http://www.dalouche.com/wordpress/2006/02/05/dns-registrars-comparison/ This CNET article gives the latest trends about digital cameras innovations. However, what about : Better Quality CCD sensors at high ISO settings ? A CCD technology that combines the sharpness of Foveon X3 sensors and color reproduction+ISO sensibility of traditional Bayer filters ? Another thing that I am wondering about is when will ... http://www.dalouche.com/wordpress/2006/02/05/digital-cameras-are-getting-better/ Any slightly experienced developer knows that once you have acquired the basic algorithmic, methodologic and design skills, such as the Imperative and Object Oriented paradigms, it is quite easy to learn another language. If you are quite new to the Java/J2EE world and want to be hired in this area (it ... http://www.dalouche.com/wordpress/2006/02/04/javaj2eejee-employment-tips-how-to-get-hired/ SpringFramework.NET is, to me, one of the best .NET Lightweight Containers available over there. More than just an Inversion Of Control framework, it features an interesting set of features such as AOP (Aspect Oriented Programming). However, I still haven't figured out whether Spring.NET has a unified framework for Data Access and ... http://www.dalouche.com/wordpress/2006/02/04/springframeworknet-still-lacking-db4o-integration/ As can be seen from this post (standblog), Novell is preparing some really cool features for Linux's next-generation Desktop.. Can't wait to have everything included by default on my Ubuntu box.. A few videos are available. http://www.dalouche.com/wordpress/2006/02/04/linux-desktop-is-getting-better/ This post from Scott Merril explains how to keep SSH sessions alive. I have experienced the same problem in the past when I was using a kind of cheap router-modem for my Internet Connection.. So, thanks scott, it's always useful to know why it happened ;-) http://www.dalouche.com/wordpress/2006/02/04/keeping-ssh-sessions-alive/ Apparently, quite a lot of blogs ( BlogORabais , Je Hais le Printemps) and news sites (Slashdot, The Register) are relaying the information... So, what is Google currently preparing ? Is this information a whole FUD started by Google , just to make this company even more popular ? In any case, ... http://www.dalouche.com/wordpress/2006/01/31/google-creating-its-own-linux-distribution/ While speaking about a work I achieved last summer, related to ServiceMix (a JBI container) and PXE ( a BPEL engine that can be embedded inside ServiceMix), a friend of mine came up to the following conclusion : In theory, theory and practice are the same whereas in practice, they are ... http://www.dalouche.com/wordpress/2006/01/26/servicemix-jbi-container-and-pxe-bpel-theory-and-practice/ Waoo.. Have you ever tried FreeNX, a free version of NoMachine's server ? This piece of software is incredible ! In two words, it's a better, secure, VNC server. A brief look at NoMachine NX explains some technical details about it... Good luck to understand the gory details ;-) http://www.dalouche.com/wordpress/2006/01/26/freenx-is-damn-crazy/ Yes, FUSE is the future !! I personnally think that it does NOT make sense to implement every protocol known to earth inside kernel-space, just to be able to mount remote folders. Implementing stuff in kernel-space implies complexity, and bloat. Added to that, why would you reinvent the wheel ? If libProtocol ... http://www.dalouche.com/wordpress/2006/01/25/fuse-is-the-future/ It is a shame to see that only 0.53% of internet users (see zdnet [fr]) use Linux... It was obvious it didn't represent many users, but so few ????? Anyways, Good luck to our lovely OS... http://www.dalouche.com/wordpress/2006/01/25/linux-053-of-internet-users/ I have recently setup a Linux server, so it was the occasion of pointing out the few things that still suck on this beautiful Operating System. Even though the distribution was Ubuntu Linux Server, the most famous Debian GNU/Linux derivative, all of these remarks apply to most other UNIXes such ... http://www.dalouche.com/wordpress/2006/01/22/10-things-that-still-suck-under-linux/ It looks like Red Hat has a position for an Evolution Hacker position...  The more Open Source positions there are, the better ! http://www.dalouche.com/wordpress/2006/01/22/evolution-hacker-position-at-red-hat/ Hi think that Trackbacks are a great invention. Everyone should turn trackbacks on. This post explains everything about trackbacks in wordpress. http://www.dalouche.com/wordpress/2006/01/22/trackbacks-are-great/