Christoph Jahn

I grew up in the beautiful city of Regensburg in Bavaria (southern Germany), which was founded by the Romans in 179 as a military camp. Since 2006 Regensburg is a UNESCO World Heritage Site.

Wikipedia has a few things to say about Regensburg (and there is also a German article). Here are a few pictures of the main spots for sightseeing. But be assured that there are many more.

One of the less known libraries of the Apache Commons project is JXPath which implements XPath (and not only for accessing Java beans but of course also DOM structures). Documentation, however, is scarce so the tutorial provided on http://www.tfo-eservices.eu/wb_tutorials/media/JXPathTutorial/PDF/JXpathTutorial.pdf is something you want to look at.

While looking for a regex reference for XML Schema I came across the site http://www.regular-expressions.info that offers a plethora of information about regular expressions in general. And as each programming language’s implementation is a bit different from the others, there is also a special section that points out these aspects. This is where I found what I was looking for, a description of  XML Schema regular expressions.

I hadn’t looked into the topic of Java decompilers for quite a while and was interested to learn from a colleague about the Java Decompiler project. It comes with either an Eclipse plug-in or a stand-alone GUI that doesn’t require installation.

In May I spent a few days on Grand Cayman and here are the pictures (finally). Enjoy!

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I recently looked into the subject of cross-platform installation. In this context I have come across the multi-platform installer IzPack (there is also an interview on InfoQ). Although this creates Java installers, as opposed to native formats like MSI or RPM which I prefer, it seems to be an interesting product. So I will spend some more time with it and keep you posted on my findings

I have been a happy user of the typesetting system LaTeX for almost 20 years. For creating the actual output (be it a DVI, PostScript or PDF file) I have usually used some home-grown script in the past. But recently, when digging through the repository of available software for my Fedora 12 system, I came across something much better: latexmk.

Apart from the expected things, like automatically recognizing when e.g. BibTeX or makeindex need to be run, it also supports a continous mode. It then monitors all the files that make up your document. And whenever one of them changes, it automatically re-creates the document. When your previewer supports auto-refresh, you can instantly see the effect of your update without any manual interaction needed.

I did not only visit New York but also the Washington DC area. Here are the pictures …

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And here are the remaining pictures from the New York trip …

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Here are some more pictures from my recent trip to New York. This time it’s everything related to the waterfront. That especially includes a trip with the Staten Island Ferry (for free!). And on the last picture you can see president Obama’s car waiting for him …

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