Ninja Monkeys! » java

Oracle buys Sun

Vaughn Dickson — Mon, 20 Apr 2009 15:29:25 +0000

IBM would’ve been a good match for Sun as they’re strong on the open source side, but Oracle buying Sun is a complete surprise. I think they’re more interested in dominating the business software market with Java and their database than doing anything major with Sun’s hardware.

Reported on Slashdot.org

Google App Engine now supporting Java virtual machine

Vaughn Dickson — Wed, 08 Apr 2009 09:12:09 +0000

Google’s just released a Java 6 virtual machine on their Google App Engine platform. It’s a sandbox environment that wraps the Google services in standard Java interfaces that should be able to run most libraries with some tweaks.

This is pretty huge, because depending on how restrictive the sandbox is we could run Scala, Groovy, Jython, JRuby, etc. on top of the same VM. Now if I can just get my head around non-relational databases.

Java performance profiling on Mac for free using Shark

Vaughn Dickson — Thu, 21 Feb 2008 08:47:33 +0000

I’ve evaluated a number of tools for Java performance profiling like JProfiler, YourKit, etc. which are all great, but $500 is expensive for a South African, and the Eclipse Test & Performance Tools don’t run on Mac OS X yet. So what’s a cheapskate to do? Use the free application that comes with Mac OS X 10.3+: Shark. Install it off the Apple optional installs on your DVD, then follow these instructions to get Shark to profile your JVM instead of the process itself.

1. Run your Java application with this command line added:

JVM 1.4: Add the following flag to your Java VM command line options: –XrunShark.
JVM 1.5 or later: Add the following flag to your Java VM command line options: -agentlib:Shark.

2. Start Shark at /Developer/Applications/Performance Tools/Shark
3. Select one of ‘Java Time Profile’, ‘Java Alloc Trace’, etc. in the first dropdown.

4. Select your java process in the last dropdown
5. Click start and run through your program.
6. Click stop and view the analysis and be glad you haven’t coughed up $500 on a commercial tool.

More information on Sharks analysis can be found on Apple’s website.

p.s. You need to use the -XrunShark option if you want to do a Java Alloc Trace, else you get the error message “The JVM Tools Interface cannot record allocation events [JavaTraceDataSource].”

I’m in the top 5% of Java programmers

Vaughn Dickson — Fri, 08 Feb 2008 14:26:31 +0000

According to BetterProgrammer.com I passed their testing better than 95% of other test takers. However, they don’t say how many other test takers there were, and you don’t really know how many were legitimate either, but I’m still proud of my result :)

Try to beat me at http://www.betterprogrammer.com

Update: Some folks have said that it’s another stupid test that expects you to know obscure details of Java syntax, but it’s definitely not. It tests your knowledge of data structures, recursion, data types, etc. So it’s more of a computer science test than a standard lame Java test.

Update 2: Maxim Glaezer, the owner and developer of betterprogrammer.com, answered my question about the number of users who have taken the test. And the results aren’t surprising.

The site started just several months ago, but since it is difficult to
motivate programmers to pass (one more) test, there are not many
registered users. A huge percentage of test takers quit after the 3rd
task, approximately 1/3 who pass the test register, other 2/3 realize
the result will not be spectacular and quit. So, there were ~600
programmers who started and completed the whole test.

I am not sure it this site ever becomes useful or popular, looks like
only 1% of all visitors dare to start the test.

So 25th out of 1800 is okay, but what worries me is that you can take the test again, which is fine if you get a bad mark, but if you keep taking the test eventually the same questions will pop up and you can just copy and paste your solutions and get 99%. Maybe a limit of 3 chances should be enforced.

Maximizing windows in Java Swing

Vaughn Dickson — Tue, 22 May 2007 08:32:49 +0000

JFrame frame = new JFrame();

// add all components

frame.pack();

frame.setExtendedState(JFrame.MAXIMIZED_BOTH);

frame.setVisible(true);

The key here is that you must call setExtendedState after any pack() methods, else it has no effect and you’ll spend two hours searching google and cursing Swing…trust me on this.