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Questions tagged [rdf4j]

Eclipse RDF4J is a Java framework for working with RDF, SPARQL, and OWL. It offers a set of libraries and APIs for parsing, writing, scalable storage and reasoning, as well as a Workbench and Server application for deployment of RDF databases. This tag should be used for all questions regarding use of the RDF4J libraries and tools.

Eclipse RDF4J is a Java framework for parsing, writing, storing, querying and reasoning with RDF, SPARQL, and OWL. It offers a set of libraries and APIs for parsing, writing, scalable storage and reasoning, as well as a Workbench and Server application for deployment of RDF databases.

Eclipse RDF4J is the successor of the OpenRDF Sesame project.

For more information see the RDF4J community website.

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org.eclipse.rdf4j vs org.openrdf

I am learning on RDF and framework to implement them from RDF4J. While exploring I came across two APIs that seem to be very similar. This is the one that RDF4J uses in its examples. These start with org.eclipse.rdf4j.... There is a very similar API…
whitehat
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How to direct RDF4J to use SPIN RDF triples when sp:text is present in imported RDF file?

I'm using RDF4J server and workbench version 2.2.2. I'm using a SPIN-capable repository in RDF4J, and I'm reading an RDF file I've created in TobBraid Composer Free Edition (TBC FE) containing many spin:construct rules. TBD FE is set to include…
Greg Cox
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Manipulate Date/Time in RDF4J for Debugging

I'm using RDF4J 2.2.1 on Windows 10 Professional 64-bit. I will have some SPIN constructor rules which are sensitive to date/time. For example, I may want to compare a triple containing an xsd:dateTime datatype property to the output of SPARQL's…
Greg Cox
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RDF4J workbench cannot query new repositories

I have a very simple setup, just rdf4j-server.war and rdf4j-workbench.war in a tomcat server. I created a new repository and the new repository worked, so I could read and write from it via my program. But when I used the workbench I could not query…
ChristophE
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Why RDF4J won't work in Bluemix Cloud Foundry

RDF4J is an apache open source graph db that i use often on my PC. It comes with 2 webApp : RDF4J-server and RDF4J-workbench (a user interface) On my PC i push the 2 wars in the same Tomcat and everything is ok. I begin an experiment to push these…
pirela
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How to load a gzipped rdf file to rdf4j Repository?

I want to load a gzipped rdf file into a org.eclipse.rdf4j.repository.Repository. During the upload, status messages must be logged to the console. The size of my rdf file is ~1GB of uncompressed or ~50MB of compressed data.
jschnasse
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how to write RDF in original format

RDF4J Newbie question - When I load this RDF from file:
kgu87
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Query partial RDF graph by using SPARQL construct

I am using an RDF4J native triplestore where several named graphs/models are stored. In my Java program, I am trying to retrieve a partial graph out of a named graph by using the SPARQL CONSTRUCT query form. The partial graph should be identified by…
phly
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Query Marklogic with RDF4J SPARQLRepository

I try to query a marklogic server (version 8) via their sparql endpoint and the sparqlrepository from rdf4j(2.1.4) but the marklogic endpoint seems to not accept these sparql queries. Code example: String sparqlEndpoint =…
ChristophE
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SPIN constraint using CONSTRUCT: where do the CONSTRUCT's triples go?

I'm using TopBraid Composer Free Edition (5.1.3) to create ontologies including SPIN constraints. I then load the resulting RDF files into RDF4J (2.0.1) and use RDF4J Workbench for testing. I'm working on SPIN constraints. Here's an example to…
Greg Cox
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RDF4J Workbench Add RDF: How do I add multiple files?

I'm using RDF4J Workbench 2.1.2. System Information Application Information Application Name RDF4J Workbench Version 2.1.2 Runtime Information Operating System Windows 10 10.0 (amd64) Java Runtime Oracle Corporation Java HotSpot(TM) 64-Bit…
Greg Cox
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Can an application directly program against GraphDB's underlying RDF4J database?

According to the GraphDB documentation, it is possible to program against its underlying RDF4J database directly. It goes against my intuition that the same database files can concurrently be accessed by two separate applications. Is this handled…
Jeroen Kransen
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RDF / lucenesail error: org.openrdf.query.QueryEvaluationException: java.util.ConcurrentModificationException

We use http://www.openrdf.org/contrib/lucenesail# search in 90% of our rdf queries. I'd like to see if anyone knows how to go about fixing the error "org.openrdf.query.QueryEvaluationException: java.util.ConcurrentModificationException" in file…
user2917629
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How to check if a SPARQL query is a query or an update in Java?

I need to parse SPARQL and SPARQL Update queries in a Java application. I tried to do this by the use of the rdf4j library. This library provides possibilities to parse Queries (e.g. QueryParserUtil.parseQuery(...) or…
Bianconeri1988
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RDF4J Workbench: Why is One SPIN Constructor Very Slow?

I apologize for the length of this posting. I am trying to make this slow rule issue reproducible. I'm using TopBraid Composer FE to create an RDF file with ontology and SPIN constructors. He purpose of the SPIN constructors is to check for…
Greg Cox
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