Configuring Joseki + Pellet + TDB
I was looking for some documentation about using TDB and Pellet
reasoser on Jena without pet peeves, didn’t found anything usable at all, so after a few
attempts I was still fighting against an ambiguity error,
whenever Joseki tries to build a dataset, the following exception pops up
18:18:49 WARN Configuration :: Failed to build dataset from description (service name: reason): cannot find a most specific type for file:///joseki-config.ttl#dataset_reason, which has as possibilities: ja:RDFDataset ja:InfModel. com.hp.hpl.jena.assembler.exceptions.AmbiguousSpecificTypeException: cannot find a most specific type for file:///Users/fmeyer/projects/semantic/ servicos/joseki/joseki-config.ttl#dataset_reason, which has as possibilities: ja:RDFDataset ja:InfModel. at com.hp.hpl.jena.assembler.assemblers.AssemblerGroup$PlainAssemblerGroup. open(AssemblerGroup.java:104) at com.hp.hpl.jena.assembler.assemblers.AssemblerGroup$ExpandingAssemblerGroup. open(AssemblerGroup.java:70) at com.hp.hpl.jena.assembler.assemblers.AssemblerBase.open(AssemblerBase.java:41) at com.hp.hpl.jena.assembler.assemblers.AssemblerBase.open(AssemblerBase.java:38) at org.joseki.DatasetDesc.newDataset(DatasetDesc.java:65) at org.joseki.DatasetDesc.initialize(DatasetDesc.java:60) at org.joseki.Configuration.processModel(Configuration.java:112) at org.joseki.Configuration.(Configuration.java:83) at org.joseki.Dispatcher.setConfiguration(Dispatcher.java:130) at org.joseki.Dispatcher.initServiceRegistry(Dispatcher.java:100) at org.joseki.Dispatcher.initServiceRegistry(Dispatcher.java:93) at org.joseki.RDFServer.init(RDFServer.java:79) at org.joseki.RDFServer.(RDFServer.java:64) at joseki.rdfserver.main(rdfserver.java:85)
We just need to define a GraphTDB as a subclass of a Model as follow to fix this issue
@prefix ja: <http ://jena.hpl.hp.com/2005/11/Assembler#> . @prefix tdb: </http><http ://jena.hpl.hp.com/2008/tdb#> . ## Initialize TDB. [] ja:loadClass "com.hp.hpl.jena.tdb.TDB" . tdb:DatasetTDB rdfs:subClassOf ja:RDFDataset . tdb:GraphTDB rdfs:subClassOf ja:Model . ## ---- A whole dadaset managed by TDB < #dataset_reason> rdf:type ja:RDFDataset ; ja:defaultGraph < #inf_graph> . < #dataset> rdf:type ja:RDFDataset ; ja:defaultGraph < #def_graph> ; . < #inf_graph> rdf:type ja:InfModel ; ja:reasoner [ ja:reasonerClass "org.mindswap.pellet.jena.PelletReasonerFactory" ; ] ; ja:baseModel < #tdbGraph> . < #def_graph> rdf:type ja:InfModel ; ja:baseModel < #tdbGraph> . < #tdbGraph> rdf:type tdb:GraphTDB ; tdb:location "DB" ; .
