On 13/05/15 15:27, Rob Vesse wrote:
I assume you'll go ahead and file a bug against Xerces?
The issue does not seem to be in Apache Xerces.
Jena is picking up the JDK XMLStreamReader implementation.
Xerces does not provide javax.xml.stream.XMLInputFactory and
XMLStreamReader at least its not in META-INF/services
It means that adding org.codehaus.woodstox:wstx-asl is a valid
workaround always as the default JDK provider is not used unless there
are no XMLInputFactory registered (ServiceLoader).
Its surprising that the JDK bug is still open as the fix for the JDK
looks small.
Andy
Rob
On 13/05/2015 14:56, "Andy Seaborne" <[email protected]> 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
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:1
19
)
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(QueryEngin
eH
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(SPARQLHan
dl
er.java:80)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.<init>(RDFClass.j
av
a:62)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RD
FC
lass.java:228)
at
de.unibonn.iai.eis.linda.querybuilder.classes.RDFClass.searchRDFClass(RD
FC
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.jav
a:
57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessor
Im
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&qu
er
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%2
3%
3E+PREFIX+owl%3A%3Chttp%3A%2F%2Fwww.w3.org%2F2002%2F07%2Fowl%23%3E++SELE
CT
+distinct+%3Fclass+%3Flabel++WHERE+%7B+%7B%3Fclass+rdf%3Atype+owl%3AClas
s%
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&q
ue
ry
=PREFIX+rdf%3A%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-n
s%
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++SEL
EC
T+
distinct+%3Fclass+%3Flabel++WHERE+%7B+%7B%3Fclass+rdf%3Atype+owl%3ACla
ss
%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%5
C%
5C
bact%22%2C%22i%22%29%29%7D+ORDER+BY+%3Fclass%0D%0A&format=text%2Fhtml&
ti
me
out=30000&debug=on
