Hi David
On Mon, Aug 29, 2011 at 4:40 PM, David Riccitelli
<[email protected]> wrote:
> Hi Rupert,
>
> I think is this one:
> http://dbpedia.org/sparql?query=SELECT+DISTINCT+?id+%0AWHERE+%7B+%0A++%7B+%0A++++?id+%3Chttp://www.w3.org/1999/02/22-rdf-syntax-ns%23type%3E+%3Chttp://dbpedia.org/ontology/Person%3E+.+%0A++++?id+%3Chttp://www.w3.org/2000/01/rdf-schema%23label%3E+?tmp1+.+%0A++++++?tmp1+bif:contains+'%22Plantar%22'+.+%0A%7D+%0A%7D+%0AORDER+BY+DESC+(+%3CLONG::IRI_RANK%3E+(?id)+)+%0ALIMIT+20+%0A&format=application/sparql-results%2Bjson
>
This corresponds to this SPARQL query:
SELECT DISTINCT ?id
WHERE {
{
?id <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://dbpedia.org/ontology/Person> .
?id <http://www.w3.org/2000/01/rdf-schema#label> ?tmp1 .
?tmp1 bif:contains '"Plantar"' .
}
}
ORDER BY DESC ( <LONG::IRI_RANK> (?id) )
LIMIT 20
this is a typical query as used by the NamedEntityTaggingEngine to lookup
an Entity with the name "Plantar" for an TextAnnotation with the
dc:type dbpedia-ont:Person
> In fact before that exception I have this one:
>
> 29.08.2011 08:51:54.939 *WARN* [1605442425@qtp-23480987-1]
> org.apache.felix.http.jetty /engines/
> (org.apache.stanbol.enhancer.servicesapi.EngineException:
> 'NamedEntityTaggingEngine' failed to process content item
> 'urn:content-item-sha1-feef2e6a8bb37b08ff71e7b2d27582ae4c640adb' with type
> 'text/plain':
> org.apache.stanbol.entityhub.servicesapi.site.ReferencedSiteException:
> Unable to execute query on remote site http://dbpedia.org/sparql with
> entitySearcher org.apache.stanbol.entityhub.searcher.VirtuosoSearcher!)
> org.apache.stanbol.enhancer.servicesapi.EngineException:
> 'NamedEntityTaggingEngine' failed to process content item
> 'urn:content-item-sha1-feef2e6a8bb37b08ff71e7b2d27582ae4c640adb' with type
> 'text/plain':
> org.apache.stanbol.entityhub.servicesapi.site.ReferencedSiteException:
> Unable to execute query on remote site http://dbpedia.org/sparql with
> entitySearcher org.apache.stanbol.entityhub.searcher.VirtuosoSearcher!
> (...)
> Caused by: java.io.IOException: Server returned HTTP response code: 500 for
> URL:
> http://dbpedia.org/sparql?query=SELECT+DISTINCT+?id+%0AWHERE+%7B+%0A++%7B+%0A++++?id+%3Chttp://www.w3.org/1999/02/22-rdf-syntax-ns%23type%3E+%3Chttp://dbpedia.org/ontology/Person%3E+.+%0A++++?id+%3Chttp://www.w3.org/2000/01/rdf-schema%23label%3E+?tmp1+.+%0A++++++?tmp1+bif:contains+'%22Plantar%22'+.+%0A%7D+%0A%7D+%0AORDER+BY+DESC+(+%3CLONG::IRI_RANK%3E+(?id)+)+%0ALIMIT+20+%0A&format=application/sparql-results%2Bjson
> (...)
>
In the earlier mail you where getting a JSONException while praising
the response of a query. Here you are getting a 500 indicating the the
dbpedia SPARQL endpoint had some problems.
Testing this query today resulted in a 200. However I could observe
strange behavior while testing.
Precisely: sending the above URL with curl -v printed the headers of
the response however after that the curl command has not terminated as
expected. It kept running until I manually terminated it.
Making the same request but without the
"&format=application/sparql-results%2Bjson" parameter I was also
getting a 200 (as expected) but this time curl terminated and printed
<sparql xmlns="http://www.w3.org/2005/sparql-results#";
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
xsi:schemaLocation="http://www.w3.org/2001/sw/DataAccess/rf1/result2.xsd";>
<head>
<variable name="id"/>
</head>
<results distinct="false" ordered="true">
</results>
</sparql>
... an empty response.
If I make a request with the above URL (including the
"&format=application/sparql-results%2Bjson") directly in the Browser I
get an empty response. As far as I know this would not be valid JSON
and could explain the JSONException as mentioned in the earlier mail.
So for me it looks like that the dbpedia.org SPARQL server has
currently some problems in writing JSON responses.
On Mon, Aug 29, 2011 at 4:51 PM, David Riccitelli
<[email protected]> wrote:
> If I run, $ curl "
> http://dbpedia.org/sparql?query=SELECT+DISTINCT+?id+%ntax-ns%23type%3E+%3Chttp://dbpedia.org/ontology/Person%3E+.+%0A++++?id+%3Chttp://www.w3.org/2000/01/rdf-schema%23label%3E+?tmp1+.+%0A++++++?tmp1+bif:contains+'%22Plantar%22'+.+%0A%7D+%0A%7D+%0AORDER+BY+DESC+(+%3CLONG::IRI_RANK%3E+(?id)+)+%0ALIMIT+20+%0A&format=application/sparql-results%2Bjson
> "
>
> I get a:
>
> { "head": { "link": [], "vars": ["id"] },
> "results": { "distinct": false, "ordered": true, "bindings": [ ] } }
>
I was not able to confirm this. The above URL is not an valid request because
SELECT+DISTINCT+?id+%ntax-ns%23type%3E+
"%ntax-ns" is not valid. Could it be that you have missed some parts
when copying this request to the mail?
However the result noted in this mail would be the expected response
if the query would not return any results.
On Mon, Aug 29, 2011 at 4:40 PM, David Riccitelli
<[email protected]> wrote:
> And then I have lots of these (at least 20):
>
> 29.08.2011 08:53:35.924 *INFO* [1605442425@qtp-23480987-1]
> org.apache.stanbol.enhancer.servicesapi.helper.EnhancementEngineHelper No
> Triple found for <urn:enhancement-fa2cfb8d-5cad-5e80-ea03-b2b39be6f404> and
> property <http://purl.org/dc/terms/type>! -> return null
> 29.08.2011 08:53:35.924 *WARN* [1605442425@qtp-23480987-1]
> org.apache.stanbol.enhancer.engines.entitytagging.impl.NamedEntityTaggingEngine
> Unable to process TextAnnotation
> <urn:enhancement-fa2cfb8d-5cad-5e80-ea03-b2b39be6f404> because property<
> http://purl.org/dc/terms/type> is not present
>
Before processing TextAnnotations the NamedEntityTaggingEngine checks
that the "dc:type" and "selected-text" properties are present for an
TextAnnotations. So if you see such warnings there must be some other
enhancement engine present that creates TextAnnotations that are
missing the "dc:type" property.
best
Rupert Westenthaler
--
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