Hi,
I want to host fuseki-server for SPARQL query. I encountered
NullPointerException when integrating inference with tdb (It's normal
without inference). The process of tdb loading is Ok. When I start the
fuseki server, it will throw the graph name null pointer exception and it
seems the tdb goes wrong. I have no idea how to fix it. Have you ever
encountered such problem or any suggestion on this problem? THX!

It seems it has nothing to do with fuseki version and OS. I have tested on
fuseki-3.4.0 and fuseki-3.5.0 on win 10 as well as ubuntu.

By the way, the RDF (in N-Triples format) file loaded into TDB is dumped by
dump-rdf tool of d2rq latest version 0.8.1

Configuration as below:

@PreFix <https://github.com/prefix> : <#> .
@PreFix <https://github.com/prefix> fuseki: http://jena.apache.org/fuseki# .
@PreFix <https://github.com/prefix> rdf:
http://www.w3.org/1999/02/22-rdf-syntax-ns# .
@PreFix <https://github.com/prefix> rdfs:
http://www.w3.org/2000/01/rdf-schema# .
@PreFix <https://github.com/prefix> tdb: http://jena.hpl.hp.com/2008/tdb# .
@PreFix <https://github.com/prefix> ja:
http://jena.hpl.hp.com/2005/11/Assembler# .

[] rdf:type fuseki:Server .
[] ja:loadClass "org.apache.jena.tdb.TDB" .
tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset .
tdb:GraphTDB rdfs:subClassOf ja:Model .

:service1 a fuseki:Service ;
fuseki:dataset :dataset ;
fuseki:name "chronicle_kg" ;
fuseki:serviceQuery "query" , "sparql" ;
fuseki:serviceReadGraphStore "get" ;
fuseki:serviceReadWriteGraphStore "data" ;
fuseki:serviceUpdate "update" ;
fuseki:serviceUpload "upload" .

:dataset rdf:type ja:RDFDataset ;
ja:defaultGraph
[ a ja:InfModel ;
ja:baseModel <#tdbGraph> ;
#Location of ontology file
ja:content [ja:externalContent
<file:///D:/apache%20jena/apache-jena-fuseki-3.5.0/run/databases/chronicle_schema.ttl>
] ;
#Enable OWL based reasoner
ja:reasoner [ja:reasonerURL <http://jena.hpl.hp.com/2003/OWLFBRuleReasoner>]
;
] ;
.

<#tdbGraph> rdf:type tdb:GraphTDB ;
tdb:dataset <#tdbDataset> .

<#tdbDataset> rdf:type tdb:DatasetTDB ;
tdb:location "D:/apache jena/tdb" .
If I don't use infmodel, I mean, with TDB dataset directly (fuseki:dataset
<#tdbDataset>), it's completely ok. If not, error as follow will be thrown.


​
SimmerChan

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