Wednesday, July 27, 2005

Jakarta Commons Chain

The Jakarta Commons Chain framework is a fairly new framework that implements the Chain of Responsibility pattern. In this article, the basics of the framework are discussed, starting with the interfaces Command, Chain, and Catalog. In addition, the reader is introduced to some packages designed for use in Web applications and learns how Commons Chain will be applied in an upcoming version of Struts. Finally, some imperfections are mentioned that are still present at the time of this writing.
rating comment: Nice overview of the Commons Chain framework, though I miss comments on applying this in realworld applications. Okay there is an example of Struts applying it (which reminds me of the Interceptors notion of JBoss AS), but I'd have preferred to read more about applying it in other applications. Nevertheless good article!

Tuesday, July 26, 2005

Screen-scraping with XQuery

XQuery is a W3C standard for extracting information from XML documents, currently spanning 14 working drafts. While the majority of interest in XQuery is centered around querying large bases of semi-structured document data, XQuery can be surprisingly effective for some much more mundane uses as well. In this month's Java theory and practice, columnist Brian Goetz shows you how XQuery can be used effectively as an HTML screen-scraping engine.
rating coment: I like this article a lot, since it provides an insight into different technologies. Although it only scratches the surface of every technology, it got me quite curious about the whole screen-scraping idea.

Persönliches Google Erweitert

Google hat seine personalisierte Suchmaschinen-Startseite um eine Lesefunktion für Web-Feeds erweitert. Darüber lassen sich beliebige Newsquellen und Blogs direkt in die Homepage integrieren.
Finde ich ne coole Sache, vor allem weil man so seine ganzen RSS Feeds unterwegs dabei hat. Ansonsten erinnert mich das Ganze stark an "My Yahoo", was ich bisher immer verwendet habe. Allerdings schlägt "Personalized Google" in Sache usability "My Yahoo" um Längen!" Man kann sich sicher darüber streiten, ob dieses Feature in Google nun unbedingt notwendig ist oder nicht, ich finde es auf jeden fall ne tolle Sache!

Memory Leaks

How do you find memory leaks in enterprise scenarios, where taking down an application and installing a profiling version is simply not an option? This article by Staffan Larsen introduces memory leaks, their associated causes, and how to find them using BEA WebLogic JRockit and the JRockit Memory Leak Detector.
rating comment: Nice illustration of memory leaks and the role of the garbage collector, unfortunately too much details on the JRockit VM Tools. I would have preferred to read more about the garbage collector in respect of memory leaks.

Monday, July 25, 2005

Code Jam 2005

Suchmaschinenbetreiber Google lädt zu seinem dritten, jährlich stattfindenden Programmierwettbewerb namens Code Jam. Interessierte können sich bei registrieren. Dort finden sich auch die detaillierten Teilnahmeregeln.
Code Jam hört sich ja cool an, aber ich hoffe nicht, dass sich da was staut!

Sunday, July 24, 2005

Business Process Modeling

Business Process Modeling (BPM) is a set of technologies and standards for the design, execution, administration, and monitoring of business processes. In this article, Mike Havey, author of Essential Business Process Modeling, briefly describes the state of BPM today and the BPM standards, then builds an ideal BPM architecture using the example of a retailer process.

Saturday, July 23, 2005

IBM boosts Harmony

IBM has committed a full time employee to work on the Apache Harmony open source JVM and class library. IBM is being careful to let the Harmony community set it's own direction and is limiting it's contributions to thoughts on design, at this point, although IBM VP Rod Smith he "is sure" that code contributions will come later.
I think this is clearly a move against sun, whereas one developer is not that much of a contribution...maybe IBM just wants to be involved. Contributing code, maybe of the J9 VM, would be a smart move of IBM, since it could turn Harmony into a serious competitor of sun.

Thursday, July 21, 2005

Package Scoping

Scopes are one of the first things we learn as Java developers. Public, private and even protected scopes are easy enough to grok, but package-private scope alludes many Java newbies.
Very interesting blog on package scoping. You should also read the comments, especially erikprice's comment is very interesting!

Folding your Windows

Fold n' Drop is a new interaction technique for seamlessly dragging and dropping between overlapping windows. It allows you to fold windows while dragging objects...
This is very cool!! Download the demo and try it yourself! You can find further instructions on the fold n' drop site!

Wednesday, July 20, 2005

When to use annotations

Since we started our EJB 3.0 implementation, I've written a lot of unit
tests and tutorials for it. Other than actually actually enjoying
writing an EJB for a change, I thought alot about when and where XML
should be used over annotations and in what situations annotations
should probably be used over XML. I came up with these rules:
  1. Use an annotation if the metadata you are applying changes the design of your class.
  2. Use an annotation if the metadata changes the design of code interacting with your class.
  3. If your application needs to be portable between app-servers or
    databases, don't use an annotation that will not allow you to be
  4. Use XML when you want to configure on a per-deployment basis.

Nice overview of when to use annotations, and when to use XML configuration with EJB 3.0. I really like the notion of looking at annotations as a kind of documentation.

Saturday, July 16, 2005

Wednesday, July 13, 2005

Interaction Design

Some applications make perfect sense to the developer, but not to the end user. Are you thinking of your GUIs in terms of what the developer needs, what the application needs, or what the user needs? In this installment of "Interaction Happens," Jonathan Simon shows how to "think holistically" about your GUI.
rating comment: Very interesting article, which gives some nice ideas of polishing your user interface. I really like the "Message Bubble" example, which is a nice alternative to a normal dialog.

Monday, July 11, 2005

Exceptions and J2EE

Javaworld has an article entitled "Exception management and error tracking in J2EE," which "provides the basis for developing a set of policies along with a supporting framework for error handling in the J2EE world."...
Nice comments and notions about Exception management in J2EE!!

Thursday, July 7, 2005

Wednesday, July 6, 2005

Dependency Injection

Dependency Injection continues to grow in popularity due to it's code simplification effects. If you've haven't had a chance to learn and apply DI yet, this new article on TSS by Dhananjay Nene will bring you up to speed on the concepts as well as illustrate how DI is done in Spring, PicoContainer, Hivemind, and XWork.

Monday, July 4, 2005