On 13/05/15 14:56, Andy Seaborne wrote:
So far we know:
It is a bug in Xerces handling of 1.1
Specifically, an NPE
XML11NSDocumentScannerImpl:scanStartElement line 356
(a big +1 to open source here)
1/ The first problem line hit is <variable name="class"/>
"/>" is the trigger.
<variable name="class"></variable> would work.
2/ It affects Xerces 2.11.0 and also the Xerces inside OpenJDK.
https://bugs.openjdk.java.net/browse/JDK-8029437
Looks like it is just the OpenJDK parser.
3/ Adding org.codehaus.woodstox:wstx-asl to the dependencies can fix it
(may depend on ordering) - e.g. add jena-text to your project (!!!).
because it picks up a different STaX parser.
Andy
On 13/05/15 14:06, Rob Vesse wrote:
Jeremy
Looks like someone else just ran into the same issue and filed a bug -
JENA-940 [1] - feel free to add a comment there indicating that this
appears to be the same issue you encounter
Apparently the issue has something to do with DBPedia adopting XML 1.1
and
a lack of support for that in Xerces (or at least the version of Xerces
Jena currently uses)
Rob
[1] https://issues.apache.org/jira/browse/JENA-940
On 13/05/2015 12:27, "Jeremy Debattista" <[email protected]>
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(QueryEngineH
TTP.java:372)
at
de.unibonn.iai.eis.linda.helper.SPARQLHandler.executeQuery(SPARQLHandler.j
ava:41)
at
de.unibonn.iai.eis.linda.helper.SPARQLHandler.getLabelFromNode(SPARQLHandl
er.java:80)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.<init>(RDFClass.jav
a:62)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RDFC
lass.java:228)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RDFC
lass.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(DelegatingMethodAccessorIm
pl.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&quer
y=PREFIX+rdf%3A%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%2
3%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+%3F
label.+++FILTER%28bound%28%3Flabel%29++%26%26+REGEX%28%3Flabel%2C+%22%5C%5
Cbact%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&que
ry
=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++SELEC
T+
distinct+%3Fclass+%3Flabel++WHERE+%7B+%7B%3Fclass+rdf%3Atype+owl%3AClass
%7
D+UNION+%7B%3Fclass+rdf%3Atype+rdfs%3AClass%7D.+%3Fclass+rdfs%3Alabel+%3
Fl
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&ti
me
out=30000&debug=on
