On 22/03/17 20:07, Dimov, Stefan wrote:
Hi all,
I'm new to Apache Jena and Fuseki. I've installed Apache Jena Fuseki as a
standalone server and I'm trying to define a very simple inference rule and
seemingly, I'm not configuring it correctly. My configuration file
config_new.ttl looks like this:
@prefix : <#> .
@prefix fuseki: <http://jena.apache.org/fuseki#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix tdb: <http://jena.hpl.hp.com/2008/tdb#> .
@prefix ja: <http://jena.hpl.hp.com/2005/11/Assembler#> .
@prefix ao: <http://ao.com> .
[] rdf:type fuseki:Server ;
fuseki:services (
<#mainservice>
) .
<#mainservice> rdf:type fuseki:Service ;
fuseki:name "mainservice" ;
fuseki:serviceQuery "sparql" ;
fuseki:serviceQuery "query" ;
fuseki:serviceUpdate "update" ;
fuseki:serviceUpload "upload" ;
fuseki:serviceReadWriteGraphStore "data" ;
fuseki:serviceReadGraphStore "get" ;
fuseki:dataset <#ao> ;
.
### In-memory, initially empty.
## This database set-up allows OWL inference.
<#ao> rdf:type ja:MemoryModel ;
ja:defaultGraph <#infGraph> .
As already mentioned on StackOverflow, this is wrong. You must put
graphs in a dataset.
<#ao> rdf:type ja:RDFDataset ;
<#infGraph> rdf:type ja:InfModel ;
ja:reasoner [ ja:rulesFrom <file:inference_rules.rules> ; ] .
Try adding a reasoner:
ja:reasoner
[ ja:reasonerURL
<http://jena.hpl.hp.com/2003/GenericRuleReasoner> ;
ja:rulesFrom <inference_rules.rules>
] ;
and make sure inference_rules.rules is accessible in the right location
to the server.
and put in a base graph:
<#infGraph> rdf:type ja:InfModel ;
ja:baseModel <#data> ;
ja:reasoner
[ ja:reasonerURL
<http://jena.hpl.hp.com/2003/GenericRuleReasoner> ;
ja:rulesFrom <...>
] ;
.
<#data> rdf:type ja:MemoryModel ;
ja:content [ja:externalContent <initial_data.ttl>] ;
.
I'm starting the server from a console with:
./fuseki-server --update --file=config_new.ttl /mainservice
You do not need the /mainservice -- it is in the config file at fuseki:name
(examples not checked - hopefully someone can confirm/correct them)
Andy
It's starting and I am able to upload some data and query it successfully from
the web-page, but seemingly it doesn't read the file inference_rules.rules.
Even if the file name is wrong or the file doesn't exist or the contents of the
file is incorrect, I don't get any errors and the rule is not working.
What am I missing?
There's a second question here. Apparently, I'm not there yet, but let me put
here the contents of inference_rules.rules. I'm trying to define a simple
transitive rule - if (A is a B) and (B is a C), then A is a C:
@prefix rdf: http://www.w3.org/1999/02/22-rdf-syntax-ns#
@prefix ex: http://example.com/
@prefix xs: http://www.w3.org/2001/XMLSchema#
@prefix ao: http://ao.com/
[isA:
(?a ao:isA ?b)
(?b ao:isA ?c)
->
(?a ao:isA ?c)
]
Did I define it correctly?
Regards,
S.
