Examples with TupleQueryResult org.openrdf.query.TupleQueryResult used on opensource projects

Example 11 with TupleQueryResult

use of org.openrdf.query.TupleQueryResult in project stanbol by apache.

the class SesameYard method find.

@Override
public final QueryResultList<Representation> find(FieldQuery parsedQuery) throws YardException, IllegalArgumentException {
    if (parsedQuery == null) {
        throw new IllegalArgumentException("The parsed query MUST NOT be NULL!");
    }
    final SparqlFieldQuery query = SparqlFieldQueryFactory.getSparqlFieldQuery(parsedQuery);
    RepositoryConnection con = null;
    TupleQueryResult results = null;
    try {
        con = repository.getConnection();
        con.begin();
        //execute the query
        int limit = QueryUtils.getLimit(query, getConfig().getDefaultQueryResultNumber(), getConfig().getMaxQueryResultNumber());
        results = executeSparqlFieldQuery(con, query, limit, true);
        //parse the results and generate the Representations
        //create an own valueFactors so that all the data of the query results
        //are added to the same Sesame Model
        Model model = new TreeModel();
        RdfValueFactory valueFactory = new RdfValueFactory(model, sesameFactory);
        List<Representation> representations = limit > 0 ? new ArrayList<Representation>(limit) : new ArrayList<Representation>();
        Map<String, URI> bindings = new HashMap<String, URI>(query.getFieldVariableMappings().size());
        for (Entry<String, String> mapping : query.getFieldVariableMappings().entrySet()) {
            bindings.put(mapping.getValue(), sesameFactory.createURI(mapping.getKey()));
        }
        while (results.hasNext()) {
            BindingSet result = results.next();
            Value value = result.getValue(query.getRootVariableName());
            if (value instanceof URI) {
                URI subject = (URI) value;
                //link the result with the query result
                model.add(queryRoot, queryResult, subject);
                //now copy over the other selected data
                for (String binding : result.getBindingNames()) {
                    URI property = bindings.get(binding);
                    if (property != null) {
                        model.add(subject, property, result.getValue(binding));
                    }
                //else no mapping for the query.getRootVariableName()
                }
                //create a representation and add it to the results
                representations.add(valueFactory.createRdfRepresentation(subject));
            }
        //ignore non URI results
        }
        con.commit();
        return new SesameQueryResultList(model, query, representations);
    } catch (RepositoryException e) {
        throw new YardException("Unable to execute findReferences query", e);
    } catch (QueryEvaluationException e) {
        throw new YardException("Unable to execute findReferences query", e);
    } finally {
        if (results != null) {
            //close the result if present
            try {
                results.close();
            } catch (QueryEvaluationException ignore) {
            /* ignore */
            }
        }
        if (con != null) {
            try {
                con.close();
            } catch (RepositoryException ignore) {
            /* ignore */
            }
        }
    }
}