How to make RDF and JSP place nicely together?

Via Gavin (via the chumpologica): An application architecture that should yield superior productivity.
Interesting stuff. I’ve been pondering something similar myself, mainly because I have a slice of an application I’m working on that I want to replace with an RDF data model and storage. To achieve this successfully I need to make sure that the data nicely dovetails with the JSP 2.0/JSTL templating environment we’ve built on top. However I don’t want to model everything as objects if I can help it, because by doing so I’m going to sacrifice some of the flexibility I gain from using RDF.
Ideally I want to gut the current Data Access Objects and replace them with node that navigates the underlying RDF graph, perhaps using an RDF query language, and then return a subset of that graph in a form that suitable for traversing with JSTL. There’s not a great deal of business logic in that slice of the application so there’s little else to change.
I had been wondering whether the technique used in RDF Twig could be generalized to creation of simple object hierarchies (Lists and Maps). Rx4RDF might be another useful place to mine for ideas.
Suggestions for other useful APIs to techniques to explore will be gratefully received.
btw, if you find that you start extending your object model to allow arbitrary property annotation, and some of those properties are actually pointers to other objects in your graph, then that’s probably a sign that you may be better off using an RDF based model. And possibly Python too but I’ve not explored that angle yet.

Get Your FOAF On: Events continued

Part of the continuing Get Your FOAF On series, this tutorial is a companion to the earlier installment on events, covering some specific types of event description.
While the RDF iCalender effort is certainly the most rigorous approach to describing events in RDF, this doesn’t mean that it’s the only way to do it and other vocabularies offer some alternatives for specific cases.
This tutorial will look at the Conference and Bio vocabularies that describe conference participation and births, deaths, and marriages.

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MusicBrainz RDF Schema

This has already circulated to a few folk, but I thought I’d share it with a wider audience.
Basically I’ve written up a first attempt at an RDF Schema for MusicBrainz. Here’s the schema and here’s the accompanying notes, including some comments on how SongBuddy exports its data as RDF and how this might be improved.
The goal here is to turn this into the official schema for MusicBrainz data (Robert Kaye seems keen to get a schema in place). So comments are very welcome.


Via Cafe con Leche I notice that Saxon 7.9 has been released. The interesting thing is that Mike Kay has founded Saxonica Limited which will offer professional services and additional modules, including a schema-aware processor as a commercial offering.
I’ve used Saxon for a long time now. It’s my XSLT processor of choice. I’ve never bothered with Xalan or other processors as Saxon has always Just Worked.
Like any good tool Saxon is adjustable enough to help you solve any particular problem. Just recently I’ve benefited from both the saxon:preview which helped me deal with a large transform and the very easy extension mechanism that allowed me to invoke some Java code during a transformation (generating a SHA1 sum for an email address).
I think it’s good news that Mike is intending to continue offering the basic product for free and wish him well in the commerical venture.

FOAF Blogrolls

I came across a posting from Matthew Haughey this morning which contained this comment:

I think developers forget that people won’t or can’t use any technology until it’s got an easy-to-use interface. I know it’s important at some level, but I couldn’t care less about say, which RDF vocabulary FOAF will use, I only care how easy it will be to add FOAF stuff to my site (best is having something do it automatically

The posting was noting that has just added XFN support.
So taking Matt’s comments to heart I whipped up a simple interface that uses FOAF to generate a blogroll.

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