On 13/05/15 13:59, Jeremy Debattista wrote:
Hi Andy,
Thanks for your reply, but I didn’t really get how you set the input stream to
1.0.
No - I don't know either.
DBpedia have just broken use of Jena in a way that breaks all previous
Jena versions. There is a lot of applications using older versions of
Jena. They have just been blocked from DBpedia.
DBpedia has always had problems with stray bad characters in output
results - this is not the way to fix that.
Please tell them.
Unfortunately, in Jena we cannot use: application/sparql-results+json as a
content type since a select query has a preset content type in the
QueryEngineHTTP class.
Its controllable:
QueryEngineHTTP.setSelectContentType
We could provide statics to set the defaults if it is not already possible.
We can put in all the adapter and and config code you like - it does not
change the issue that DBpedia has made a change that breaks apps and we
can't do anything to help already released core.
Andy
Cheers,
Jer
On 13 May 2015, at 14:38, Andy Seaborne <[email protected]> wrote:
The DBpedia response has a processing directive:
<?xml version="1.1" ?>
not XML "1.0" (or default) Setting it to "1.0" and I worked for me. I don't
see any XML 1.1 feature being used.
It fails because there is no XML 1.1 parser registered.
((The results aren't schema conforming anyway distinct= and ordered= aren't in
the standard, not that it is checked))
There aren't many XML 1.1 parsers about and the uptake of XML 1.1 is low. There
are issues due to the strictness for character sets in XML parsing - invalid
documents becoming valid is a big deal of that document is a business process
document i.e. $$$ is involved and its a security issue.
Anyone know how to ignore the processing directive and have Jena setup the
parser factory anyway?
Workaround: use a different like the JSON format.
Andy
On 13/05/15 12:27, Jeremy Debattista wrote:
Hi Rob,
Yes that is what I suspect as well, even though when I use a curl function with
content negotiation [1], the returned results look good (and well formed).
Anyway, this is the complete error stack:
com.hp.hpl.jena.sparql.resultset.ResultSetException: Failed when initializing
the StAX parsing engine
at
com.hp.hpl.jena.sparql.resultset.XMLInputStAX.<init>(XMLInputStAX.java:119)
at com.hp.hpl.jena.sparql.resultset.XMLInput.make(XMLInput.java:73)
at com.hp.hpl.jena.sparql.resultset.XMLInput.fromXML(XMLInput.java:42)
at com.hp.hpl.jena.sparql.resultset.XMLInput.fromXML(XMLInput.java:37)
at
com.hp.hpl.jena.query.ResultSetFactory.fromXML(ResultSetFactory.java:312)
at
com.hp.hpl.jena.sparql.engine.http.QueryEngineHTTP.execSelect(QueryEngineHTTP.java:372)
at
de.unibonn.iai.eis.linda.helper.SPARQLHandler.executeQuery(SPARQLHandler.java:41)
at
de.unibonn.iai.eis.linda.helper.SPARQLHandler.getLabelFromNode(SPARQLHandler.java:80)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.<init>(RDFClass.java:62)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RDFClass.java:228)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RDFClass.java:222)
at com.servlet.routes.BuilderRoute.getProperties(BuilderRoute.java:172)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
Cheers,
Jeremy
[1] curl -H "Accept: application/sparql-results+xml" -g
"http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=PREFIX+rdf%3A%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E+PREFIX+rdfs%3A%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E+PREFIX+owl%3A%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E++SELECT+distinct+%3Fclass+%3Flabel++WHERE+%7B+%7B%3Fclass+rdf%3Atype+owl%3AClass%7D+UNION+%7B%3Fclass+rdf%3Atype+rdfs%3AClass%7D.+%3Fclass+rdfs%3Alabel+%3Flabel.+++FILTER%28bound%28%3Flabel%29++%26%26+REGEX%28%3Flabel%2C+%22%5C%5Cbact%22%2C%22i%22%29%29%7D+ORDER+BY+%3Fclass%0D%0A”
On 13 May 2015, at 12:32, Rob Vesse <[email protected]> wrote:
What is the error message you get?
It is not unheard of for Virtuoso (the software that powers DBPedia) to
produce bad output particularly if the data has not been appropriately
sanitised so I would suspect Virtuoso before suspecting Jena in a case
like this
Rob
On 13/05/2015 10:16, "Jeremy Debattista" <[email protected]> wrote:
Dear All,
I am trying to query the DBpedia SPARQL endpoint using the
QueryExecutionFactory sparqlService and execSelect(), but I’m given the
following error: com.hp.hpl.jena.sparql.resultset.ResultSetException:
Failed when initializing the StAX parsing engine
The query in question is
PREFIX rdf:<http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX
rdfs:<http://www.w3.org/2000/01/rdf-schema#> PREFIX
owl:<http://www.w3.org/2002/07/owl#> SELECT distinct ?class ?label
WHERE { {?class rdf:type owl:Class} UNION {?class rdf:type rdfs:Class}.
?class rdfs:label ?label. FILTER(bound(?label) && REGEX(?label,
"\\bact","i"))} ORDER BY ?class
which gives a result in dbpedia sparql web interface [1].
The code in question is the following:
public static ResultSet executeQuery(String uri, String queryString) {
Query query = QueryFactory.create(queryString);
QueryExecution qexec = QueryExecutionFactory.sparqlService(uri, query);
try {
ResultSet results = qexec.execSelect();
return results;
} finally {
}
}
After debugging, the problem seems to be related to how the XML parser is
reading the stream input. Would you have any other idea how I can go
around it?
Best Regards,
Jeremy
[1]
http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query
=PREFIX+rdf%3A%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23
%3E+PREFIX+rdfs%3A%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3
E+PREFIX+owl%3A%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E++SELECT+
distinct+%3Fclass+%3Flabel++WHERE+%7B+%7B%3Fclass+rdf%3Atype+owl%3AClass%7
D+UNION+%7B%3Fclass+rdf%3Atype+rdfs%3AClass%7D.+%3Fclass+rdfs%3Alabel+%3Fl
abel.+++FILTER%28bound%28%3Flabel%29++%26%26+REGEX%28%3Flabel%2C+%22%5C%5C
bact%22%2C%22i%22%29%29%7D+ORDER+BY+%3Fclass%0D%0A&format=text%2Fhtml&time
out=30000&debug=on
