How make org.openrdf.rio parser supports Turtle documents?

Question

I have a java project on Eclipse that read R2RML (.ttl) file. I am using R2RMLReader from it.unibz.inf.ontop.r2rml.R2RMLReader which uses Open RDF Rio org.openrdf.rio.Rio, here is the method code:

public static ArrayList<TripleMaps> readR2RMLFile() {
        String mappingFile= "/path/to/Desktop/r2rmlFile.ttl";

         R2RMLReader reader = null;
          try {
            reader = new R2RMLReader(mappingFile);
          } catch (Exception e) {
            e.printStackTrace();
          }
          ArrayList<OBDAMappingAxiom> axioms = reader.readMappings();
          for (OBDAMappingAxiom ax : axioms)
            System.out.println(ax);
        return null; 
    }

However, the R2RMLReader throws this error:

org.openrdf.rio.UnsupportedRDFormatException: No parser factory available for RDF format Turtle (mimeTypes=text/turtle, application/x-turtle; ext=ttl)
    at org.openrdf.rio.Rio.createParser(Rio.java:198)
    at it.unibz.inf.ontop.r2rml.R2RMLManager.<init>(R2RMLManager.java:71)
    at it.unibz.inf.ontop.r2rml.R2RMLReader.<init>(R2RMLReader.java:63)
    at it.unibz.inf.ontop.r2rml.R2RMLReader.<init>(R2RMLReader.java:54)
    at TripleMaps.readR2RMLFile(TripleMaps.java:170)

What am I missing? Are there any jar files that should I add to the project?

I see this implementation on many tutorials and they use .ttl file format. However, in my project it not working.

I looked into different solutions this org.eclipse.rdf4j.rio.UnsupportedRDFormatException for Turtle format and this RDF4J RIO UnsupportedRDFormatException when adding data to an HTTPRepository using a stand-alone application

However, I am not using maven I downloaded all jar files and added it to the project.

I looked in http://archive.rdf4j.org/javadoc/sesame-2.8.9/org/openrdf/rio/RDFFormat.html , the openrdf/rio/RDFFormat should support Turtle.

"The file extension .ttl is recommend for Turtle documents"

How make org.openrdf.rio parser supports Turtle documents?

if you don't use Maven for whatever reason, then indeed have to download the missing JARs and moreover, the correct version if those - that's exactly the point Maven makes way easier (most of the times ...) — UninformedUser, Nov 17 '22 at 06:40
what jars am I missing? because I added all needed jars, however it not support ttl format. How could I solve this issue? — نظام الارشاد الطلابي, Nov 17 '22 at 13:34

Jeen Broekstra · Answer 1 · 2022-11-19T04:36:22.943

0

You are missing the actual Turtle parser implementation, which is contained in a separate jar file from the Sesame Rio parser APIs (see https://search.maven.org/artifact/org.openrdf.sesame/sesame-rio-turtle ).

As suggested in the comments as well, I'd urge you to save yourself a world of pain: use maven to solve these kinds of dependency problems.

Also this: I'm not sure exactly what you're trying to achieve of course, and I don't know what version of the Ontop platform you're using, but the mention of org.openrdf packages indicates it's an old version. That package name is from the old Sesame project, which was replaced by the Eclipse RDF4J more than 6 years ago. I'm also pretty sure that Ontop itself has updated its dependencies to use RDF4J instead of Sesame for a while now. You may want to try upgrading to a more recent version.

edited Nov 19 '22 at 04:36

answered Nov 19 '22 at 03:11

Jeen Broekstra

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How could I use Maven? I never use it before. I am working on java project Eclipse, are there any useful tutorial on how to use maven to add dependency to my project? – نظام الارشاد الطلابي Nov 21 '22 at 14:46
If you google "getting started with maven in eclipse" you'll find several good tutorials. It may take a little investment to learn it, but worth it if you plan to do more java development in the future. – Jeen Broekstra Nov 21 '22 at 18:13

How make org.openrdf.rio parser supports Turtle documents?

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