Like all software, Deployit plugins should be build automatically, deployed and tested whenever possible. Below I will explain how to setup continuous integration and testing for Deployit plugins. The general idea is that if you’re creating a larger set of plugins for Deployit, it makes sense to try to build and deploy them as often as possible so you can catch errors early. We found that it is really easy to create plugins that work fine in isolation but fail when they are deployed together. Luckily it is also easy to catch these kinds of errors as I will show below.
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All I wanted to do was create a number of plugins and examples for Deployit using the different techniques available. While working on examples I was frustrated by having to clean up remainders of previous attempts, so following in the footsteps of greater men than my humble self (most notably professor Knuth who created TeX so he could finish writing a series of books on computer science) I first wrote a script to create junk in the Deployit repository and then get rid of it in one sweeping go.
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A while ago my colleague Olav Maassen asked a question on our company mailing list about the best book to read to learn OSx development. His question made me think not about the best book but about how I learned new programming languages in the past.  Read more

Getting the Java out of your Scala, part 2

I’m still trying to get rid of old habits, to shake of my winter hide, so to speak, and create some real Scala in stead of ScaVa (i.e. Java with a Scala syntax). If you’re interested you can bear witness to my struggle on GitHub (ShoppingList on GitHub). This story came about because I asked some colleagues for help. We ended up rewriting loops in several ways.
What I’ll show you is some alternatives to classic loops over collections.
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With everybody going mobile, we could not stay behind. This meant we had to create an Android application, because we (Bram Neijt, Arno den Hond and your chronicler) do not own one of them fancy iPhones.
Also, Android is way cooler.
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To get some grip on the configuration of the Weblogic domains and servers at my current client, I created a tool that reads domain config files and translates them in a graph. I decided to solve this problem in Scala, mainly because I read about its powerful native XML parsing capabilities. Parsing XML turned out to be a total no-brainer, but I managed to learn something about how to solve problems the Scala way, so this is a story about Scala rather than parsing XML in Scala.
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We’ve been busy for a couple of weeks now refactoring a fairly complex code base of just under 500 classes. None of us really knew all the details about this part of the system, but we didn’t let that stop us of course. After some regrouping/-shuffling/-factoring/*ing, the whole thing built OK and all unit tests were green again. All that was left to do was fix the Fitnesse tests. I remember thinking this should be easy since we had all those green unit test.

Evil laughter sounds.
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Software vendors have hijacked a potentially useful concept by pushing heavy weight complex tools like ESBs. The goal of this article is to find out which of those tools we really need so we can stay away from unnecessary complexity. I’ll do that by describing the infrastructure services we really need and how these services can be implemented in the simplest possible way.

Software depends on other software because we don’t want to build systems from scratch. Each piece of software your code depends on may:
- change the address or name by which it is known
- change the technology it is implemented in
- be unavailable when you need it
- live on a different server or in the same process
- be connected through infrastructure that cannot be trusted
- speak a different language
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Most IT careers start with a programming job: you write code in one of the popular programming languages as part of a team. As your experience grows you start to get bored with software: you’ve been working with more or less the same technology and tool set for a couple of years and you need something new to keep yourself going. That’s the point where you have several options like becoming a project manager, coach, analyst or middleware expert. This story is about another option: becoming an architect.
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In an attempt to better understand the ideas behind ‘Life Beyond Distributed Transactions, an Apostate’s Opion.’ by Pat Helland, I’m going to try to explain how the concept would work out for a time-honored example: the good old transfer of money from one account to the other, the archetype of all distributed transactions because we want to make absolutely sure we don’t lose money.
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