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Roundabout

Posted by editor on April 20, 2006 at 7:44 AM PDT


More on real-time Java slot cars

Last week, we had an Also in Java Today item about programming in real-time Java, specifically the JavaOne Slot Car Programming Challenge. If you couldn't imagine it in your mind, it helps to have pictures of just what your code is up against.

James Gosling provides just that kind of perspective in his blog Fun in real time, in which he shows Greg Bollella setting up the track, along with pictures of the 80 tiny sensors that will be programmers' only indication of where the cars are and what they're doing.

Oh, and you thought you'd just track progress from one sensor to another? Think again.

These sensors are simple photocell gates (the kind used to detect paper moving through a printer) placed along the slot. They give a simple 0/1 indication of whether or not the car is passing by the sensor. To make life harder, all of the sensors are ored together. There's only 1 bit of input - two, actually - one sensor gets a seperate bit: it's the start/finish line. So you have to count. Accurately. No missing sensor pulses.

Ready for this? It will be interesting to see not only who wins, but how their code works.


Also in today's Weblogs, Dru Devore looks at
DataSources with Sun Java System Creator and JBoss:
"We are currently using Creator to create a testing and QA front end for the enterprise application we are developing. After success with working with services we finally needed to hit a configuration database to show all the configuration options available to different applications and users."

Marina Sum writes about "Practical, useful, and up-to-date course material, illuminating examples and exercises, let alone knowledgeable instructors with passion and expertise" in her blog
Valuable Training Not To be Missed: Java University Program.


In our Feature Article, Jacobus Steenkamp looks at
Bringing Swing to the Web: "Unless you are implementing a thick enterprise client such as an applet or a Java Web Start application--options which have their own sets of size, deployment, and compatibility issues--you might think that there is not that much scope for using Swing within web applications, or indeed Java EE. You would, however, be making a mistake; there is no reason why web and Swing development should be mutually exclusive. In this article, we will look at putting one of Swing's most overlooked (and basic) features to work inside a web application."


In Also in
Java Today
,

ClientJava has collected a pair of deployment horror stories in the entry Why I will never deploy with Java Web Start again. It starts with Keith Lea describing the problems experienced with a class scheduler at Rensselaer Polytechnic Institute, including user-experience complaints, scripting woes, and JNLP file confusion. Kyle Cordes adds a few miseries of his own and advocates a native alternative.

The latest release of the Java platform includes a number of new system monitoring and management features. In Using Java platform management beans, developers May Glover Gunn, George Harley, and Caroline Gough team up to get you started using this API. After a quick overview of the java.lang.management package, they guide you through a number of short practical scenarios to probe the performance of a running JVM.


In Projects and
Communities
,

Danny Coward takes a look "beyond Mustang" and what he sees is Modularity on the Java SE horizon. "It still amazes me that under these competing demands, Java the language and Java the platforms have remained so consistent. But in places, the signs of age and stress are showing. In order that Java can continue to be many things to many people, its natural to look to ways to flex under the stress, rather than snap"

The interview article Java ME Luminary - Hinkmond Wong of Sun Microsystems Ventures "Beyond Google Maps" previews a JavaOne session advocating Java ME for the client side of AJAX applications. "Don't get caught up in the notion that you need JavaScript to do AJAX", Wong says, "a MIDlet running on a cell phone can automatically check a Web 2.0 back-end service and integrate with it using common protocols like REST and XML."


In today's Forums,
byhisdeeds says
Swing applications cause 100% CPU usage on Fedora Core 5:
"I have recently upgraded from FC4 to FC5 and noticed that my Swing applications running under mustang b80 exhibit 100% CPU usage. I tried the SwingSet2 demos and the JColorChooser demo causes the CPU to run at 100%. I tried 1.5.04 and the CPU usage is the same. On a FC4 machine the CPU usage is 90% but that machine is using the MESA libraries. Anybody have a similar experience. I'm running the 2.6.16-1.2080_FC5 kernel with the NVIDIA 8756 driver."

alexlamsl speaks up for annotations in
Re: method implementation should not be an @Override?:
"You might hate them, but these features help us to trust the code beyond trusting whoever writing "know his/her stuff and think before his/her compile" To have mistakes like these taken care of in a formal and concrete way always helps - at least by using the annotation the team will have one less thing to worry about, which potentially means that they will get along with each other better."


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More on real-time Java slot cars