31.07.04

Sourcebeat: Spring Live

Today I bought myself Spring Live by Matt Raible from Sourcebeat. Sourcebeat offers books in a very unique way. You subscribe to a book for 12 months, getting updates every couple of months about the book you subscribed to. This is a great deal IMO, since a lot of books in the programming world are outdated very fast. But with this electronical publishing model Sourcebeat breaks this vicious circle and delivers good books.
So far I just read two chapters of "Spring Live" but it is a great introduction to the Springframework with a lot of code and examples and how to solve things. I like it and recommend it to anyone interested in the Spring Framework.
Since it comes with a lot of good code, I guess I will use it to set up some things for work and private playground.
Has anyone experience with other titles of sourcebeat?

Posted by Karsten at 20:13 | Comments (3) | TrackBack

27.07.04

Moved Resources

Since my webspace at Webspace4All is limited, I moved all bigger files to my university server.
The good thing is, that I am now able to include others work as well, so if you like to see your master thesis (Diplomarbeit) published at my thesis entry, just drop me a comment or mail.

Posted by Karsten at 13:01 | Comments (0) | TrackBack

25.07.04

6 Best Practices for J2EE Architecture

6 Best Practices for J2EE Architecture is a nice how to for learning some very important things in J2EE apps:
Lesson 1: Never Shortcut Server-Side Validation
Lesson 2: Security is Not an Add-On
Lesson 3: I18N is Not a Just a Buzzword Anymore
Lesson 4: Avoid Common Mistakes With MVC Presentation
Lesson 5: Don't Be Embarrassed by POJOs
Lesson 6: Data Access Does Not Mandate O/R Mapping

And I think it is a good advice for the Springframework as well, since all the things it advocates are solved by Spring very nicely.

Posted by Karsten at 00:03 | Comments (0) | TrackBack

24.07.04

Inversion of Control/Dependency Injection

Seit einiger Zeit geistert ein neues Muster (Pattern) durch die OO-Gemeinde: Inversion of Control (IoC) bzw Dependency Injection.
IoC ist die ältere Bezeichnung, welche dann Martin Fowler in seinem weitreichenden Artikel (Inversion of Control Containers and the Dependency Injection pattern) umnannte in Dependency Injection.
Die immer komplizierter werdenden J2EE Spezifikationen haben sicher einen Grossteil dazu beigetragen, dass dieser neue Ansatz derart populär geworden ist und in den letzten Jahren neue Frameworks mit IoC nur so aus dem Boden geschossen sind.
"Inversion of Control" / "Dependency Injection" ist ein Pattern, das die Verbindung verschiedener Software-Komponenten (sowie meist das SW-Testen) schneller und einfacher macht.
Wer sich näher dafür interessiert, empfehle ich den oben genannten Artikel von Martin Fowler zu lesen, bzw. einen Blick auf die Dokumentationen der folgenden Frameworks zu werfen:

Posted by Karsten at 16:10 | Comments (0) | TrackBack

22.07.04

SW-Entwicklung und Entropie

Eine nette Anekdote zum Thema SW-Entwicklung und Entropie:
Ein Arzt, ein Bauingenieur und ein Softwareentwickler diskutieren darüber, welches der älteste Beruf der Welt ist. Der Arzt sagt: "Da Gott Eva aus der Rippe von Adam schuf und dafür eine Operation notwendig war, kann ich mit Recht behaupten, dass Arzt der älteste Beruf der Welt ist." Der Bauingenieur meint dazu: "Aber schon viel früher steht, dass Gott die Ordnung von Himmel und Erde aus dem Choas formte. Als erstes war daher Gott ein Bauingenieur und daher ist mein Beruf der älteste."
Der Softwareentwickler lehnt sich zurück und sagt selbstbewusst: "Aber wer denkt ihr denn hat das Chaos erschaffen?"
;)

Posted by Karsten at 11:32 | Comments (0) | TrackBack

20.07.04

Einführung: Springframework

Bis heute gibt es noch keine deutschsprachige Einführung in das Springframework (dt: Frühlingsrahmenwerk ;)), weder beim Java Magazin noch beim Java SPEKTRUM ist ein Artikel darüber erschienen, dabei ist es somit das beste Java Framework das ich kenne.
Seit längerem interessiere ich mich für und arbeite mit dem Springframework und bin von ihm hellauf begeistert.
Leider gibt es nur englischsprachige Einführungen, hier mal eine kleine Auswahl:

Was ist Ihre Meinung zum Spring Framework?

Posted by Karsten at 22:32 | Comments (0) | TrackBack

19.07.04

Interview with Rod Johnson

Interview With Rod Johnson
I can strongly recommend to view this interview which durates 30 minutes. In it Rod Johnson (Founder of The Spring Framework; Author of 'J2EE without EJB') talks about the springframework, AOP and other things in the J2EE world.
Alll in all I really like these Tech Talks. It is great to hear and see the interview instead of merely reading it. It is easier to consume and remember.

Posted by Karsten at 17:00 | Comments (0) | TrackBack

Internationalized data in Hibernate

Just read Gavin Kings article about Internationalized data in Hibernate on TheServerSide.com and can recommend it. In one of my projects we had a similar problem o storing language dependent values in a table, but Gavin Kings solution seams nice.

Posted by Karsten at 08:47 | Comments (0) | TrackBack

18.07.04

Wiki evaluation

After having a closer look at Wiki software I continued with a Wiki evaluation of PM Wiki. MediaWiki and PHPWiki are more powerful and got a greater feature set, but I chose PM Wiki for its simplicity. But I must confess that I got no need for a wiki.
But due to my research I also found the softlinks of a c't article about wikis. Maybe in a later project I might use a wiki, but not for now. I am very happy with my blog so far.

Posted by Karsten at 21:48 | Comments (0) | TrackBack

Website: java.blogs

Today I registered my blog at java.blogs after I read them almost daily since over a year. I like the site since the blogs there really deal with java things only and I like the daily email with the most favourite blogs. So I do not have to go there and search for readworthy things. A really good feature.
If you are interested in Java/J2EE things I can strongly recommend this source. They also provide a nice search function, so if you are interested in comments about a product or so you can look at what others wrote about it and therefore it is a nice aggregator place.
I merely hope that 30% blog entries in my Java/J2EE category are enough for their knock out description of "Your blog must be 'largely' to do with Java".
;)
You can find my Weblog at java.blogs with some stats about the usage.

Posted by Karsten at 16:11 | Comments (0) | TrackBack

17.07.04

Rudi Völler

Als grosser Fan von Rudi Völler habe ich natürlich auch schon die Rudi Comeback Petition unterzeichnet und kann sie nur jedem nahelegen.
Mayer-Vorfelder ist der Schwachmann beim DFB. Der muss endlich gehen.
Es gibt nur einen Rudi Völler!

Posted by Karsten at 12:40 | Comments (0) | TrackBack

16.07.04

Wiki Software

Wikis are becoming more and more Content Management System light. Best represantative of a Wiki is the Wikipedia. A friend of mine brought me to the idea of having a closer look at Wikis.
The best sources of Wikisoftware are at Wikipedia (WikiSoftware) and c2.com (WikiEngines)
I will have a closer look at some PHP versions (PM Wiki, PHP Wiki, MediaWiki) now.

Posted by Karsten at 20:54 | Comments (0) | TrackBack

XML Linking und Adressing Languages (XPath, XPointer,XLink, XInclude)

In one of my university courses (Hauptseminar eLearning-Systeme) I held a presentation about XML Linking und Adressing Languages (XPath, XPointer,XLink, XInclude).
You can find the resources here:

Posted by Karsten at 14:58 | Comments (0) | TrackBack

14.07.04

How-To: Diplomarbeit

Kurz nachdem ich meine eigene Diplomarbeit online gestellt habe, stiess ich auf den iX Artikel "Diplomarbeiten schreiben und publizieren" und wurde dadurch angeregt.
In dem Artikel werde einige Tips gegeben und die Linksammlung am Ende des Artikels ist sehr gut. Als weitere Ressourcen kann ich euch folgendes empfehlen:

  • verschiedene Bücher zum Thema Diplomarbeit zumindest mal anlesen und reinschauen
  • Diplomarbeiten normgerecht verfassen ist besuchenswert, da es hier eine Musterdiplomarbeit gibt, welche die entsprechenden DIN Normen erfüllt. Wusste selber nicht, dass es solche Normen gibt. Darüber hinaus ist es für Microsoft Word Freunde eine gute Vorlage zur Erstellung. Ich selber habe es als Vorlage benutzt.
  • Recherche in Fachdatenbanken, wie Sie bei E-Fellows.net (als Stipendiat) angeboten werden
  • Konferenzbände zum Thema durchblättern (sind meistens in der Unibibliothek vorhanden)
  • meine Diplomarbeit zum Thema "A Web-based Medical Image Database System"
  • mein Diplomarbeitsvortrag (TODO)

Viel Spass und Erfolg dabei!

Posted by Karsten at 17:38 | Comments (0) | TrackBack

09.07.04

A Web-based Medical Image Database System

As I stated already in my projects I wrote my master thesis (German: Diplomarbeit) at the Nanyang Technological University, Singapore.
You can find it online here form today on: A Web-based Medical Image Database System (WebMIDS)

And here is the Abstract:

In this report a web based medical image database is introduced. First, the requirements due to the domain of medical images in the context of a web application are specified and evaluated. This evaluation led to the aim of building a secured web application with new query functions at almost no costs.
The project is embedded in a brief description of current approaches and solutions in the domain of medical image databases.
For the implementation, J2EE is used together with the Expresso Framework. J2EE was chosen because of its strong libraries and maturity. The Expresso Framework provides useful functionalities for this project such as user management, a secured workflow and an Object-to-Relational mapping. These functions are combined with a vital development community and so Expresso was given preference over other frameworks.
Although DB2 with its Image Extender would have been preferred, MySQL was chosen as database system for the implementation due to limited funds. MySQL is a free, reliable and fast database and the lack of some functions are no big drawback for this system and are overcome by the implementation of the application.
The database design is a good reduction to the essentials, serving the different needs of users from a medical and a non-medical background.
A dedicated server was set up with Linux as the operating system and with Tomcat as servlet container. The features of the system are described in a user manual and an administrator manual. Features include the uploading and the retrieval of images with a normal web browser via the Internet. The implementation will be up and running at http://mrcas.mpe.ntu.edu.sg after an in-house test phase.
To make this system a long-lasting one some future extensions are outlined and the name WebMIDS was chosen.

For this thesis I got a grade of 1,3 which is equivalent to A- from Prof. Dr. Donald Kossmann, who was teaching at my home university back then.
The biggest junk was the implementation of the web application, which is not included since the NTU wanted to keep the code.

Posted by Karsten at 11:05 | Comments (0) | TrackBack

playing around with my websites

Tonight I played a bit with my websites and the functionality they offer and installed a couple if things.
First of all I finally managed to install Gallery on karstenvoges.de. But I guess I'll keep my gallery on the university server for a while to be on the safe side with regard to traffic and backup.
Then I installed the php bulletin board (phpBB) on mynozomi.de. I got some ideas about a forum, but nothing finished yet, so it is just a place to play.
Finally I moved Desiree's Weblog and my testblog to use MySQL in the backend.
That's it for now, but it is nice to see how things work and to play around a bit.

Posted by Karsten at 01:52 | Comments (0) | TrackBack

08.07.04

Erik's Linkblog

Erik's Linkblog is one of the greatest sources of links, regarding the Java, IT and mobile news.
I stumbled accross Erik's site after having some referrers in my webstats coming from his linkblog. So I had a look at it and I am a regular reader of it.
So I can strongly recommend it, since it is a good source for a quick Java/IT/mobile overview what is going on in the blogworld and what is interessting.

Posted by Karsten at 00:00 | Comments (0) | TrackBack

07.07.04

Homepage Besitzer sind introvertiert

Laut Psychologen der Technischen Universität Chemnitz bin ich introvertiert!
Denn wer eine Webseite im Internet sein eigen nennt ist unsicherer und kann schlechter mit Kritik umgehen.
Also wer von Euch hatte nochmal was gegen meine Heimseite gesagt? Sauerei!!!!
Naja, also ich kann das jetzt mal ja nicht so ganz glauben, aber wenn sie meinen. Ausserdem sind 300 Personen auch nicht gerade repräsentativ, oder?
Interessant ist es aber dennoch, wobei ich mir sicher bin, dass die Weblogbeitreiber eher sicherer sind im sozialen Umgang. Aber wer weiss.

Posted by Karsten at 22:19 | Comments (1) | TrackBack

Impressed by Springframework

I used the JDBC part of the Springframework to connect to an Oracle DB and call a stored procedure. So for the beginning I simply used the DriverManagerDataSource since it was sufficient for the beginning. But after having a greater load and the need for a connection pool I switched to Apache's Jakarta Commons DBCP and was impressed how easy it is to switch. I merely copied the .jar into the WEB-INF libs and changed my beans-config.xml by replacing the datasource class name of the bean definition with "org.apache.commons.dbcp.BasicDataSource".
And that's it!
Magic .... :)

Posted by Karsten at 09:51 | Comments (0) | TrackBack

06.07.04

Resources: Software test

This is a short overview about some resources related to software testing. After attending a lecture about testing of software last year at my university I went for a certificate for ISTQB Certified Tester - Foundation Level. I can strongly recommend this education/certificate since it gives you good advice on how to test and insight views into testing.
The International Software Quality Institute (iSQI) also helds a couple of big events like:

  • World Congress for Software Quality
  • CONQUEST 2004
  • iMPROVE 2004

    For German readers I can highly recommend:

  • Basiswissen Softwaretest von Andreas Spillner, Tilo Linz
  • Software-Test von Georg E. Thaller
  • Unit Tests mit Java. Der Test-First-Ansatz von Johannes Link, Peter Fröhlich
    and a good tool list as well as white papers is available from Imbus AG.

    For the Java world JUnit.org is the tool to know and the place to go for further information about the test-first or test-driven development methods.
    Fostering my testing capabilities is on my tbd. list and I will write some more thoughts about this subject soon.

    Posted by Karsten at 00:04 | Comments (1) | TrackBack
  • 05.07.04

    Kurzfilm: Stapelfahrer Klaus

    Stapelfahrer Klaus ist ein Kurzfilm mit viel schwarzem Humor und ist eine gelungene sarkastische Mischung zwischen den Lehrfilmen "Der siebte Sinn" (der Sprecher ist auch der selbe) und Splatter Filmen. Die Musik ist ein weiterer Klassiker, da sie sehr eindringlich ist und mit ihrer Fröhlichkeit ein Kontrast zu manchen bösen Szenen ist.
    Das Bonusmaterial ist zwar mit 75 Minuten um ein vielfaches länger als der eigentliche Kurzfilm mit knapp 10 Minuten, ist jedoch nur bedingt ein Mehrwert.
    Insgesamt ist Stapelfahrer Klaus ein gelungener Kurzfilm, den man immer mal wieder auf Parties o.ä. zeigen kann.

    Posted by Karsten at 23:26 | Comments (3) | TrackBack

    04.07.04

    Squashen in München

    Squashen ist einer meiner Lieblingssportarten, weil er wahnsinnig schnell ist und man so richtig gemein sein kann bzw. sogar muss. Am aktivsten habe ich den Sport in Singapur betrieben, da es dort auf dem Campus kostenlose Courts gab und sie in nur 2 minuten von meinem Zimmer aus zu erreichen waren. Hier in Deutschland ist es zwar nicht einer der billigsten Sportarten, aber fast alle Sportzentren bieten Studentenermässigungen an. Bisher getestet habe ich die folgenden:

  • Squash Center Schwabing, Winzererstr. - zentral gelegen, immer günstig ohne voranmeldung, kleine Sauna inklusive, Superfreundliches Personal
  • Tennis u. Squash Center, Zielstattstr. - weiter weg, dafür sehr geräumige Anlage mit Tennis und einer grossen Sauna mit Tauchbecken. Billig weil man sogar bis zu zwei Stunden spielen kann.
  • Park Club Nymphenburg - gemütlich, Besonderheit: Schwimmbecken/Pool im Saunabereich

    Hier sind auch zwei Übersichten (Squash Anlagen PlZ 8, Squash Courts München)

    Posted by Karsten at 18:52 | Comments (1) | TrackBack
  • 01.07.04

    Webstatistic for karstenvoges.de in June

    June is over and my first month of blogging as well and therefore it's time for a resume:
    I got a total of 1500 unique visitors which sums up to a almost 9000 hits and 300 MB of traffic. Not to bad for a starter. ;)
    Although it was a busy month I managed to write 32 new entries with the following top five pages (with page impression between 100 and 800):
    How-To: Avoid NullPointerExceptions
    Article on Spring, Struts and Hibernate
    Holland gegen Niederlande
    Mitfeierzentrale
    How-To: Comments in JSPs

    What was astonishing for me was the fact that I have a couple of regular readers of my RSS Feed already and that 150 people came to me via search engines.
    There are a lot of other useful and interesting informations in my stats, but they will be published next month.
    (all informations are based on my AWStats webstatistics)

    Posted by Karsten at 16:29 | Comments (0) | TrackBack