javasparqlapache-jenatdb

Querying Agrovoc with Jena TDB Api

i have an issue querying Agrovoc Agrovoc Rabbits result in my java application. While am able to retrieve information about rabbits like concept. But when i try retrieving attribute information like concept label, broader, broader label I get their urls instead of their descriptions. So my question is how do I get the descriptions or would i say the values of those urls i am able retrieve. And as well how do I query for broader concept, narrower concepts, is used as, entry terms attributes. And how do I get all information about the search query (as in all attribute information and description)? I have attached what i have been able achieve so far

import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.ModelFactory;
import org.apache.jena.tdb.TDBFactory;
import org.apache.jena.util.FileManager;

public class TDBCreator {
public static final String THESAURUS_FILE = "C:\\Users\\GREEN\\Desktop\\wordnet\\agrovoc_rdf/agrovoc_2017-05-04_core.rdf";
public static final String TDB_DIRECTORY = "C:\\Users\\GREEN\\Desktop\\wordnet\\agrovoc_rdf/tdb";

public Model createTDB() {
    Model model = ModelFactory.createDefaultModel();
    model = TDBFactory.createDataset(TDB_DIRECTORY).getDefaultModel();
    InputStream thesaurusStream = FileManager.get().open(THESAURUS_FILE);
    model.read(thesaurusStream, null, "RDF/XML");
    return model;
}

public static void main(String[] args) {
    new TDBCreator().createTDB().close();;
}
}

This TDBCreator file creates the TDB file for me while the Agrovoc.java queries the 

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import org.apache.jena.graph.NodeFactory;
import org.apache.jena.graph.Triple;
import org.apache.jena.query.Dataset;
import org.apache.jena.query.Query;
import org.apache.jena.query.QueryExecution;
import org.apache.jena.query.QueryExecutionFactory;
import org.apache.jena.query.QueryFactory;
import org.apache.jena.query.QuerySolution;
import org.apache.jena.query.ResultSet;
import org.apache.jena.query.ResultSetFormatter;
import org.apache.jena.query.Syntax;
import org.apache.jena.rdf.model.Literal;
import org.apache.jena.rdf.model.Model;
import org.apache.jena.rdf.model.RDFNode;
import org.apache.jena.rdf.model.Resource;
import org.apache.jena.sparql.algebra.Algebra;
import org.apache.jena.sparql.algebra.Op;
import org.apache.jena.sparql.algebra.op.OpBGP;
import org.apache.jena.sparql.core.BasicPattern;
import org.apache.jena.sparql.core.TriplePath;
import org.apache.jena.sparql.core.Var;
import org.apache.jena.sparql.engine.QueryIterator;
import org.apache.jena.sparql.engine.ResultSetStream;
import org.apache.jena.sparql.path.PathFactory;
import org.apache.jena.sparql.syntax.ElementPathBlock;
import org.apache.jena.tdb.TDBFactory;
import org.apache.log4j.Logger;

public class Agrovoc {

private static Agrovoc instance;

private final Logger LOGGER = Logger.getLogger(getClass());

private Model model;

private Agrovoc() {
    loadModel();
}

public static Agrovoc getInstance() {
    if (instance == null) {
        instance = new Agrovoc();
    }
    return instance;
}

private void loadModel() {
    File directory = new File(TDBCreator.TDB_DIRECTORY);
    if (!directory.exists()) {
        directory.mkdirs();
    }
    model = TDBFactory.createDataset(TDBCreator.TDB_DIRECTORY).getDefaultModel();
    if (model.isEmpty()) {
        model = new TDBCreator().createTDB();
    }
}


public void queryTerm(String label) {

    ElementPathBlock pattern = new ElementPathBlock();

    Var varConceptLabel = Var.alloc("conceptLabel");
    Var varConcept = Var.alloc("concept");
    Var varBroader = Var.alloc("broader");
    Var varBroaderLabel = Var.alloc("broaderLabel");
    Var varLiteralForm = Var.alloc("literalForm");

    final String SKOS_URI = "http://www.w3.org/2008/05/skos-xl#";
    final String SKOS_CORE_URI = "http://www.w3.org/2004/02/skos/core#";

    pattern.addTriple(new Triple(varConceptLabel, NodeFactory.createURI(SKOS_URI + "literalForm"), NodeFactory.createLiteral(label, "en")));
    pattern.addTriple(new Triple(varConcept, NodeFactory.createURI(SKOS_URI + "prefLabel"), varConceptLabel));
    pattern.addTriplePath(new TriplePath(varConcept, PathFactory.pathZeroOrMoreN(PathFactory.pathLink(NodeFactory.createURI(SKOS_CORE_URI + "broader"))), varBroader));
    pattern.addTriple(new Triple(varBroader, NodeFactory.createURI(SKOS_URI + "prefLabel"), varBroaderLabel));
    pattern.addTriple(new Triple(varBroaderLabel, NodeFactory.createURI(SKOS_URI + "literalForm"), varLiteralForm));

    Op op = Algebra.compile(pattern);
    QueryIterator queryIterator = Algebra.exec(op, model);

    List<String> resultVars = new ArrayList<String>();
    resultVars.add("conceptLabel");
    resultVars.add("concept");
    resultVars.add("broader");
    resultVars.add("broaderLabel");
    resultVars.add("literalForm");

    ResultSet rs = new ResultSetStream(resultVars, model, queryIterator);

    while (rs.hasNext()) {
        QuerySolution qs = rs.nextSolution();
        Literal literal = qs.getLiteral("literalForm");
        RDFNode type = qs.get("conceptLabel");
        RDFNode type2 = qs.get("concept");
        RDFNode type3 = qs.get("broader");
        RDFNode type4 = qs.get("broaderLabel");

        System.out.println(type.toString());
        System.out.println(type2.toString());
        System.out.println(type3.toString());
        System.out.println(type4.toString());
        System.out.println(literal.getString());
    }

    //return false;

}
}

attached is the result i got from my java code implementation

I also tried running Sparql query i got an empty result

 public void queryTerm(String term) {
    //String tdb = "/usr/local/src/javadev/onld/tdb";
    Dataset dataset = TDBFactory.createDataset(TDBCreator.TDB_DIRECTORY);
    StringBuilder sb = new StringBuilder();
    sb.append("PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> ");
    sb.append("PREFIX rdfs:  <http://www.w3.org/2000/01/rdf-schema#> ");
    sb.append("PREFIX skos: <http://www.w3.org/2004/02/skos/core#> ");
    sb.append("PREFIX foaf: <http://xmlns.com/foaf/0.1/> ");
    sb.append("PREFIX text: <http://jena.apache.org/text#> ");

    //sb.append("SELECT * "); 
    //sb.append("WHERE { ?s ?p ?o  } LIMIT 10 "); 
    //sb.append("SELECT ?label ");
    //sb.append("{ ?s text:query (skos:altLabel '" + term + "' 3) ;  ");
    //sb.append("skos:prefLabel ?label ");
    //sb.append("}");
    //sb.append("SELECT ?definition ");
    //sb.append("WHERE{");
    //sb.append(term).append(" skos: definition ?definition.");
    //sb.append("FILTER (lang(?definition) = 'en'");
    //sb.append("}");

    sb.append("SELECT DISTINCT ?concept ?searchLabel ");
    sb.append("WHERE {");
    sb.append("{ ?concept skos:prefLabel ?searchLabel. } UNION ");
    sb.append("{ ?concept skos:altLabel ?searchLabel. } ");
    sb.append("FILTER (regex(str(?searchLabel), 
    \"").append(term).append("\",").append("\"i\")) ");
    sb.append("FILTER (lang(?searchLabel) = \"en\")");
    sb.append("} LIMIT 10");



    //        sb.append("SELECT ?uri ?em { ");
    //        sb.append("?uri skos:prefLabel \"Japan\"@en . ");
    //        sb.append("OPTIONAL { <http://aims.fao.org/aos/agrovoc/c_4039> 
    //skos:exactMatch ?em } .");
    //        sb.append("}");

    String queryo = "SELECT ?conceptURI ?label "
            + "\nWHERE { "
            + "\n ?conceptURI ?pred1 _:b1 . "
            + "\nFILTER( ?conceptURI = <" + 
    "http://aims.fao.org/aos/agrovoc/" + term + "> )"
            + "\n FILTER(?pred1 = <" + SKOSXLALTLABEL + "> || "
            + "?pred1 = <" + SKOSXLHIDDENLABEL + "> || "
            + "?pred1 = <" + SKOSXLPREFLABEL + "> ) ."
            + "\n_:b1 <" + SKOSXLLITERALFORM + "> ?label ."
            + "}";

        String queryString = queryo;//sb.toString();
        System.out.println (queryString);
        Query query = QueryFactory.create(queryString);
        QueryExecution qexec = QueryExecutionFactory.create(query, 
        dataset.getDefaultModel());
        try {
            int resultSetSize = 0;

            ResultSet results = qexec.execSelect();
            // Output query results 
            ResultSetFormatter.out(System.out, results, query);
            System.out.println(results.getRowNumber());
            while (results.hasNext()) {
               resultSetSize++;
               QuerySolution solution = results.nextSolution();
               Iterator varnames = solution.varNames();
               System.out.println(varnames.next());
               HashMap<String, String> hm = new HashMap<String, String>();
               while (varnames.hasNext()) {
                    String name = (String) varnames.next();
                    RDFNode rdfnode = solution.get(name);
                     System.out.println("rdf node name, type: " + name);
                      if (rdfnode.isLiteral()) {
                          Literal literal = rdfnode.asLiteral();
                          String nodeval = literal.getString();
                          hm.put(name, nodeval);
                          System.out.println(nodeval);
                    } else if (rdfnode.isResource()) {
                         Resource resource = rdfnode.asResource();
                         String nodeval = resource.toString();
                         hm.put(name, nodeval);
                         System.out.println(nodeval);
                    }

                }
           }
    }

    finally {
        qexec.close();
    }

    System.out.println ("Done.");
}
Solution

  • That query works on the latest Agrovoc dataset (Core, 03 Jul 2017):

    PREFIX skos-xl: <http://www.w3.org/2008/05/skos-xl#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>

SELECT ?concept ?conceptLabel ?broaderConcept ?broaderConceptLabel WHERE {

  # set the search term
  VALUES ?conceptLabel {"rabbits"@en}

  # get the concept matching the term
  ?concept skos-xl:prefLabel ?conceptLabelNode .
  ?conceptLabelNode skos-xl:literalForm ?conceptLabel .

  # get the broader concepts
  ?concept skos:broader ?broaderConcept.

  # and their labels
  ?broaderConcept skos-xl:prefLabel ?broaderConceptLabelNode .
  ?broaderConceptLabelNode skos-xl:literalForm ?broaderConceptLabel .

  # in English language only
  FILTER(LANGMATCHES(LANG(?broaderConceptLabel), 'en'))
}

    Output (I used Stardog triple store)

    enter image description here