Comparing XML in a JUnit test

Today I tried to compare 2 XML documents in a JUnit test. One was created with Altova's MapForce, the other was the result of a new XmlBeans document (BTW, both are nice products). Notice that these XML documents use a slightly different notation for the main namespace:

Document one:

<?xml version="1.0" encoding="UTF-8"?> <Message xmlns="http://www.a.nl/a10.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="C:/longpath/a10.xsd"> <MessageHeader>....

Document two:

<?xml version="1.0" encoding="UTF-8"?> <a:Message xmlns:a="http://www.a.nl/a10.xsd"> <a:MessageHeader>....

Here is what I tried:

1. org.w3c.dom.Document.equals. Well, that goes nowhere.

2. org.dom4j.Document.equals. Same.

3. XMLUtil's XMLAssert.assertXMLEqual. Bummer, works alright, but it says that Message and a:Message are different and they are not (they're in the same namespace!).

4. Juxy's XMLComparator.assertXMLEquals. No go, same result.

5. I took a short look at the site of XSLTunit. It says that XSLTunit is a proof of concept. Furthermore, this one is also targetted at XSLT testing. So I decided to skip it.

6. Reading a bit closer I noticed that XMLUtil 1.0 released in April 2003 (wow, that's old), has a followup: XMLUtil 1.1beta1 released in April 2007 (wow, that's new). The website says they fixed the namespace thing! Unfortunately they didn't (yet, I hope).

7. The final solution: with some String.replaces, I just removed the namespace stuff and the schema location from the documents. XMLUtil 1.0 now works nicely with very good diff messages.

Update 2007-05-24 I was quite wrong. XmlUnit does notice the differences in namespace usage (and puts a message in the exception), but it does not fail until it sees a real difference. The real difference turned out to be whitespace. By adding the code added below, the differences disappear.

XMLUnit.setControlParser("org.apache.xerces.jaxp.DocumentBuilderFactoryImpl"); XMLUnit.setTestParser("org.apache.xerces.jaxp.DocumentBuilderFactoryImpl"); XMLUnit.setSAXParserFactory("org.apache.xerces.jaxp.SAXParserFactoryImpl"); XMLUnit.setTransformerFactory("org.apache.xalan.processor.TransformerFactoryImpl"); XMLUnit.setIgnoreWhitespace(true);

Firewall gone crazy!

Today I saw the solution to one of my weirdest problems ever. We have been searching for about a whole week why our JEE application would suddenly stop. The problem was that it took at least an hour to reproduce it (if at all), and even then we could find next to nothing in the logs. We only started to see the light when we noticed the difference between environments where the error was reproducable, and where is was not reproducable: the firewall.

Turns out the firewall between the application server and the database server would stop all trafic on the JDBC connection after an hour if idling, without actually killing the connection. Weblogic, and all other applications we tried, totally freak out when this happens. What on earth did the creators of that firewall think? When you kill a connection, then kill it! Do not just stop the data flow!

Well anyway, the solution? We now let Weblogic 'test' the connection every 10 minutes. Apparently, the firewall is happier when there is some traffic now and then.

Agile Web Development with Rails, 2nd edition - Book review

About time for another book review: Agile Web Development with Rails, 2nd edition, written (mostly) by Dave Thomas.

The book shows you all facets of developing a Rails application. This is actually a big improvement over the first edition. That one did not even talk about migrations. There have been a lot of changes in Rails, and these are reflected in the second edition.

Just like the first edition, the second edition is well written and has the same structure: the first chapters walk you through creating a new application, the latter chapters provide more insight in the separate building blocks of Rails. Unfortunately the book never really goes to the bottom of things (though its pretty good in the Active Record area); there is simply too much to cover. So this book is probably not a good buy if you are already an experienced Rails developer and are prepared to find information about new Rails features on the internet.

So although it took me a couple of months to read this book from cover to cover, my conclusion on this book is short: this is a must-have for any new Rails developer.

Aslak Hellesøy to speak on RubyEnRails 2007!

I just heard that Aslak Hellesøy will speak at the RubyEnRails 2007 conference! If want to know more about Behavior driven development (BDD), or love to hear more about RSpec, come to the conference!

RubyEnRails 2007 site is live! (Dutch)

Vanaf vandaag kunnen mensen zich aanmelden voor RubyEnRails dag 2007! Op de website http://2007.rubyenrails.nl kan je je aanmelden met je OpenID.

Het sprekers gedeelte op de pagina is nog niet volledig. De lijst met sprekers zal zo spoedig mogelijk worden aangevuld. Er zullen diverse presentaties plaatsvinden over o.a. RESTful ontwikkeling, Behaviour Driven Development, Radiant en het Camping Framework.

Dus ben jij een Ruby On Rails specialist of ben je gewoon geïnteresseerd in Ruby of Ruby on Rails? Meldt je dan nu aan! Deelname is overigens geheel gratis!

Wicket article translated to French

My article Backward compatible AJAX development with Wicket has just been tranlated to French by ZedroS! Nice work Joseph!

New layout

I liked the little dots, but they were also a little too psychedelic. With 9 days to go for my blog's first anniversary, I decided it was time for a new layout: Tictac blue.