Over the past few days, I’ve thrown together a simple Java GUI application to query SPARQL endpoints that purport to have file format information. The results have been less than sparkling. The only endpoint that I’ve been able to query successfully is the one for DBPedia (http://dbpedia.org/sparql), and the data there, extracted from infoboxes on Wikipedia pages, is too inconsistent for structured queries to be of much use.
The endpoints for Pronom (http://test.linkeddatapronom.nationalarchives.gov.uk/sparql/endpoint.php) and P2 (http://p2-registry.ecs.soton.ac.uk/SPARQL/) just aren’t responding, and I can’t find a published endpoint for UDFR. If anyone can help me out with these, maybe I can make some more progress.
What I have to show for my effort so far is a beginner’s knowledge of SPARQL and an application that can easily be tailored to query any SPARQL HTTP endpoint. If anyone’s interested in seeing it, let me know.
Looks like someone managed to find the UDFR SPARQL: http://www.openplanetsfoundation.org/blogs/2012-09-10-file-identification-using-fido-and-udfr-registry
Thanks! I just grabbed the code for that Python program, It calls SPARQLWrapper(“http://udfr.org/ontowiki/sparql/”) , which, though it seems odd (why under ontowiki?), is apparently the endpoint URI. As a quick test I plugged it into my code for querying DBPedia, and got back an empty result set. This is reasonable, since the query is all wrong for UDFR, but is proof of life.
Sorry there was a problem with the triplestore for the Linked Data instance of PRONOM. I think I’ve now fixed it and a simple query on the SPARQL endpoint returned results.
Still getting the same thing. Am I using the correct URI for a direct SPARQL endpoint? I’m using (http://p2-registry.ecs.soton.ac.uk/SPARQL/). If I enter that as a URL in a browser I get a web form.
I’m talking the TNA one http://test.linkeddatapronom.nationalarchives.gov.uk/sparql/endpoint.php
Much better. I didn’t get any results on my first try, but at least it’s responding now. Thanks!
Make sure you tick the “show results inline” box