JVM

Free lunches, mousetraps and the Actor model

Andrew Glover — Tue, 02 Mar 2010 19:01:25 -0500

A politician once mused

A free lunch is only found in mousetraps.

Read more ...

Oracle to take its time building the perfect JVM -- but where's Da Vinci?

Josh Fruhlinger — Mon, 01 Mar 2010 20:56:52 -0500

As you may or may not have heard, Oracle has announced its JVM strategy, or at least part of it. Action is needed because the post-merger company has one of those problems that you sort of want to have, in that it now owns two highly regarded JVMs: JRockit, which came along with the BEA acquisition in 2008, and HotSpot, which had been Sun's. Say what you will about Oracle, but they don't necessarily fall prey to "not invented here" syndrome, and are generally open to using acquired technology if it betters something already in their portfolio.

Read more ...

Book Review: Programming Scala

Andrew Glover — Thu, 10 Dec 2009 18:04:06 -0500

One more than one occasion, I’ve found myself yearning for a more functional paradigm that facilitates easier concurrency programming on the JVM.

Read more ...

Comparing Scala and Groovy via ScalaTest and easyb

Andrew Glover — Mon, 16 Nov 2009 16:40:25 -0500

Because it’s my bag, I’ve recently taken to learning Scala.

Read more ...

Increasing Tomcat’s memory

Andrew Glover — Tue, 18 Aug 2009 10:38:56 -0400

If you happen to casually peruse the Grails documentation, you might notice the following note regarding memory (please note, man, that the emphasis has been added by yours truly):

If memory is not a problem on your server then allocate a large amount of memory, such as 512M or more. Also use the server VM option. EG: (-server -Xms512M -Xmx512M). Usually it is better to set both min and max heap size to the same in server applications.

Read more ...

Java specs and governance

Josh Fruhlinger — Fri, 15 May 2009 00:52:00 -0400

Here's something that may come as a surpise: Did you know that there hasn't been a JVM spec put out since 1999? If you want to build a modern JVM, you need to start with that decade-old document and then work your way through the various JSRs that have been approved since then.

Read more ...

Tim Bray on the future of Java web development

Andrew Glover — Sat, 14 Feb 2009 16:55:00 -0500

Not long ago, I had the delight of talking with Tim Bray of Sun Microsystems about his thoughts regarding Java web development for JavaWorld’s Java Technology Insider.

Read more ...

Cannot compile Java Class.

satyadmv — Fri, 13 Feb 2009 00:14:34 -0500

I have installed java into D:/Program Files/Java
I opened the command prompt.Reached C:\.
I have a Test.java file in C:\.
Now when i run the command javac Test.java , it throws and error saying javac not found.

I copied the same Test.java to D:\.
In the cmd prompt i set the current directory as D:\.
Now i ran the cmd javac Test.java, it worked.

May i know the reason for getting this error in the first scenerio.
I couldnt understand the reason why it happened.

Java Beginner

Leveraging closures

Andrew Glover — Mon, 09 Feb 2009 18:27:30 -0500

Because it’s my bag, I recently found myself writing some code that read various .csv files containing data related to similar concepts (why that data is in various .csv files isn’t germane to the story, baby, so just keep reading); that is, each file contained slightly different data but all the data was inter-related. Accordingly, what I did with the data once I read it was both similar and different. For example, regardless of file, first, I had to see if a particular item (in a row) existed elsewhere (i.e.

Read more ...

Write once, run everywhere (but some places better than others)

Josh Fruhlinger — Fri, 19 Dec 2008 02:00:19 -0500

It's always a bit of of a tug-of-war when it comes to Java's write once, run anywhere philosophy (and, what with Java divided into three main streams with many subsections an profiles and the like, it really is more of a philosophy than anything else). Do you go for maximum portability? Do you try to improve performance on some platforms, but not others? But if you take the latter route, why not just write native code?

Read more ...

Neil McAllister on the future of VMs

Josh Fruhlinger — Thu, 16 Oct 2008 20:26:28 -0400

It's a kind of lame blog post that boils down to, "Here, read this other blog post," but -- if you are working in a VM-based language -- and, if you're reading JavaWorld, I think you are -- you really ought to read this post from Neil McAllister on InfoWorld. He discusses the place that we've found ourselves -- with VMs supporting multiple languages, and running across multiple platforms. He also offers a vision of the future that he admits is unlikely but intriguing:

Read more ...

Rise of the Java Virtual Machines

Josh Fruhlinger — Tue, 07 Oct 2008 20:04:28 -0400

Forgive me for circling repeatedly around this point, but the possibility that the Java Virtual Machine might long outlive the Java language itself is becoming increasingly intriguing to me. More interesting posts are coming out of the JVM Language Summit, including this longish one from John Rose. Rose works on the Da Vinci Machine Project, which is specifically tasked with making the JVM more hospitable for non-Java languages.

Read more ...

JVM language summit: Getting the ball rolling?

Josh Fruhlinger — Tue, 30 Sep 2008 02:21:43 -0400

I've been kind of intrigued by the rumbling growth of JVM languages -- that is, other programming languages that can be compiled into JVM-ready bytecode. The first JVM language summit is just wrapping up, and my guess is that the folks who attended will be energized and responsible for big things to come.

Read more ...

Every single language now running on the JVM

Josh Fruhlinger — Thu, 17 Jul 2008 14:29:57 -0400

All the "Java is dying" people have profoundly missed the point: Java may thrive and Java may wither, but every single language ever created for computing purposes will eventually run on the JVM, so nobody cares. The latest is 50-year-old LISP, which now can be run off of your favorite Java Virtual Machine, because, you know, why not?

Read more ...

Anatomy of a blog blowup

Josh Fruhlinger — Tue, 08 Jul 2008 10:14:29 -0400

How does rage ripple across the rather insular world of Java blogs? Well, here's a good example. First, Warner Onstine writes a post in which he basically praises Maven, but gripes that its support for the non-Java JVM languages he likes to use is lacking. So far so good, but he slaps on the rather dramatic title "Is Maven Going Away?"

Read more ...

Sun to offer JVM on awesome 3G smartphone! (cough from HP cough)

Josh Fruhlinger — Mon, 07 Jul 2008 18:41:36 -0400

Sun's JVM will now be available in binary form on that slick new smartphone that everyone's talking about -- the HP iPaq 900! (crickets chirping)

Read more ...

Warning! Polyglottism not all sunshine and unicorns!

Josh Fruhlinger — Fri, 13 Jun 2008 18:19:28 -0400

There's been a healthy discussion in the Java blogosphere lately about polyglottism, which, if you believe its boosters, is going to simultaneously kill off Java and entrench the JVM as the basis of programming for years to come. But Dhananjay Nene points out an awkward downside: performance. Turns out you can't have all these languages working together without taking a performance hit, even if they do all compile to Java bytecode. Ooops!

Read more ...

Today in Java death watch

Josh Fruhlinger — Fri, 06 Jun 2008 02:11:41 -0400

We return to our occasional series in which put our ear to the ground to answer a question crucial to all of our jobs: Is Java dying? Opinions are mixed!

Read more ...

JVM