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Posted to users@jena.apache.org by Svatopluk Šperka <is...@fit.vutbr.cz> on 2011/05/17 14:47:05 UTC
Parsing SPARQL using ARQ
Hi,
I'm using Jena's ARQ to parse a large amount of URI encoded queries. I would like to ask if someone would have a tip for the best way to preprocess queries before feeding them to ARQ.
Problem is that if I use simple URI decoding everything gets decoded.
For example, if I have encoded query:
%0APREFIX%20foaf%3A%20%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2F%3E%0APREFIX%20p%3A%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fproperty%2F%3E%0ASELECT%20%2A%20WHERE%20%7B%20%0A%20%20%20%20%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20p%3Aabstract%20%3Fabstract.%0A%20%20%20%20%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20foaf%3Apage%20%3Fwiki.%20%0A%20%20%20%20%20%20OPTIONAL%20%7B%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20foaf%3Adepiction%20%3Fimg.%7D%0A%20%20%20%20%20%20FILTER%20%28lang%28%3Fabstract%29%20%3D%20%27en%27%29%0A%20%20%20%7D%0A
it turns into
\nPREFIX foaf: <http://xmlns.com/foaf/0.1/>\nPREFIX p: <http://dbpedia.org/property/>\nSELECT * WHERE { \n <http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson> p:abstract ?abstract.\n <http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson> foaf:page ?wiki. \n OPTIONAL {<http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson> foaf:depiction ?img.}\n FILTER (lang(?abstract) = 'en')\n }\n"
which cannot be parsed because of quotes in http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson.
Is there some canonical way how to do the preprocessing correctly ?
Thank you very much.
Svatopluk Šperka
Re: Parsing SPARQL using ARQ
Posted by Andy Seaborne <an...@epimorphics.com>.
java.net.URLDecoder should do whatever is necessary.
Andy
On 17/05/11 13:47, Svatopluk Šperka wrote:
> Hi,
>
> I'm using Jena's ARQ to parse a large amount of URI encoded queries.
> I would like to ask if someone would have a tip for the best way to
> preprocess queries before feeding them to ARQ.
>
> Problem is that if I use simple URI decoding everything gets
> decoded.
>
> For example, if I have encoded query:
>
> %0APREFIX%20foaf%3A%20%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2F%3E%0APREFIX%20p%3A%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fproperty%2F%3E%0ASELECT%20%2A%20WHERE%20%7B%20%0A%20%20%20%20%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20p%3Aabstract%20%3Fabstract.%0A%20%20%20%20%20%20%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20foaf%3Apage%20%3Fwiki.%20%0A%20%20%20%20%20%20OPTIONAL%20%7B%3Chttp%3A%2F%2Fdbpedia.org%2Fresource%2FThomas_%22Scotch_Tom%22_Nelson%3E%20foaf%3Adepiction%20%3Fimg.%7D%0A%20%20%20%20%20%20FILTER%20%28lang%28%3Fabstract%29%20%3D%20%27en%27%29%0A%20%20%20%7D%0A
>
> it turns into
>
> \nPREFIX foaf:<http://xmlns.com/foaf/0.1/>\nPREFIX
> p:<http://dbpedia.org/property/>\nSELECT * WHERE {
> \n<http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson>
> p:abstract
> ?abstract.\n<http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson>
> foaf:page ?wiki. \n OPTIONAL
> {<http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson>
> foaf:depiction ?img.}\n FILTER (lang(?abstract) = 'en')\n
> }\n"
>
> which cannot be parsed because of quotes in
> http://dbpedia.org/resource/Thomas_"Scotch_Tom"_Nelson.
This is not a simple encoding problem.
Either the original query had " in them in which case it's bad (it
should have %22), or if it did then that gets encoded into %2522
%25 is % itself. %2522 is encoded %22
Andy
> Is there some canonical way how to do the preprocessing correctly ?
>
> Thank you very much.
>
>
> Svatopluk Šperka
>