The Ironism


The Crypt




Java 8 + Light Weight Threads

The last couple of days I’ve been playing around with Quasar from the fine folks at Parallel Universe. “What’s that then?” I hear you ask. It’s an API and a runtime library that promises light weight threads for the JVM, called Fibers, and all the stuff you can do with that, like light weight channels for [...]


Unit Tests with Guice and Warp Persist

Note: this post is cross-posted on Yesterday I needed to do some unit testing for a project using Guice and Warp Persist. And one thing that seems to be lacking, or wasn’t to be found be me yesterday, is the kind of unit testing you can do with Spring, where each method is wrapped by a transaction which is rolled back [...]


A Google Analytics Plugin for Nexus

Note: this post is cross-posted on Since Firebase Community Edition uses Maven heavily, I realized I’d like to track our Nexus repository in Google Analytics. The Nexus Book says that there exists such a plugin already, but apparently now one knows where it is. So here’s my attempt to write a simple one. If [...]


A Java Concurrency Bug, and How We Solved It

Note: this post is cross-posted on Everyone agrees that good debugging is critical. But it is not entirely trivial when it comes to multi-threaded applications. So here’s the story how I tracked down a nasty bug in the Java5 ReentrantReadWriteLock. Update 15/4: To be a bit clearer, the Java bug in question is on 1) Java [...]


New Article: Real Time BI

Note: this post is cross-posted on Since I’ve spent some time discussing complex event processing in various contexts the last weeks, I thought I’d write up a small article about it. And lo, here it is.I do point out in the beginning that the article is primarily targeted towards gambling networks, however it can [...]


Class Loading and AOP

Note: this post is cross-posted on I have a new article up, Debugging Class Loading with AOP, in which I briefly discuss how Aspect Oriented Programming (AOP) using AspectJ can be used to debug class loading, in particular in instances where a system have multiple class loaders.It does not cover how to use the load time [...]


Singletons… Again!

Perhaps I’m being a bit grumpy today, but this article rubs me the wrong way. It describes the Singleton pattern in Java but contains some problems. And one of the is a pet peeve of mine. The article claims: There can only be one singleton instance per JVM == Plain wrong in every respect. Singletons are good for object pooling [...]


Re: The Open Source Frameworks I Use

The Codist asks what open source frameworks we use. Now, he says frameworks, but it looks more like libraries and utilities. Which is fine by me as I generally tend to avoid the larger frameworks, and just as The Codist himself wrote my own web framework for my regular site. So, without further ado, here’s some regulars: Jetty [...]