Examples with QuerySolution org.apache.jena.query.QuerySolution used on opensource projects

Example 16 with QuerySolution

use of org.apache.jena.query.QuerySolution in project jena by apache.

the class ResultSetApply method apply.

public void apply() {
    proc.start(rs);
    for (; rs.hasNext(); ) {
        QuerySolution qs = rs.next();
        proc.start(qs);
        for (String varName : rs.getResultVars()) {
            RDFNode node = qs.get(varName);
            // node may be null
            proc.binding(varName, node);
        }
        proc.finish(qs);
    }
    proc.finish(rs);
}

Example 17 with QuerySolution

use of org.apache.jena.query.QuerySolution in project jena by apache.

the class ResultSetUtils method resultSetToStringList.

/**
     * Extracts a List filled with the binding of selectElement variable for each
     * query solution, turned into a string (URIs or lexical forms).  
     * Exhausts the result set.  Create a rewindable one to use multiple times. 
     * @see org.apache.jena.query.ResultSetFactory
     */
public static List<String> resultSetToStringList(ResultSet rs, String selectElement, String literalOrResource) {
    // feature suggested by James Howison
    List<String> items = new ArrayList<>();
    while (rs.hasNext()) {
        QuerySolution qs = rs.nextSolution();
        RDFNode rn = qs.get(selectElement);
        if (rn.isLiteral())
            items.add(((Literal) rn).getLexicalForm());
        else if (rn.isURIResource())
            items.add(((Resource) rn).getURI());
        else if (rn.isAnon()) {
            items.add(((Resource) rn).getId().getLabelString());
        } else
            throw new ARQException("Unknow thing in results : " + rn);
    }
    return items;
}

Example 18 with QuerySolution

use of org.apache.jena.query.QuerySolution in project jena by apache.

the class ResultSetUtils method resultSetToList.

/**
     * Extracts a List filled with the binding of selectElement variable for each
     * query solution as RDFNodes (Resources or Literals).
     * Exhausts the result set.  Create a rewindable one to use multiple times. 
     *   
     * @see org.apache.jena.query.ResultSetFactory   
     */
public static List<RDFNode> resultSetToList(ResultSet rs, String selectElement) {
    // feature suggested by James Howison
    List<RDFNode> items = new ArrayList<>();
    while (rs.hasNext()) {
        QuerySolution qs = rs.nextSolution();
        RDFNode n = qs.get(selectElement);
        items.add(n);
    }
    return items;
}

Example 19 with QuerySolution

use of org.apache.jena.query.QuerySolution in project jena by apache.

the class ExTDB5 method main.

public static void main(String... argv) {
    // Direct way: Make a TDB-back Jena model in the named directory.
    String directory = "MyDatabases/DB1";
    Dataset dataset = TDBFactory.createDataset(directory);
    // Potentially expensive query.
    String sparqlQueryString = "SELECT (count(*) AS ?count) { ?s ?p ?o }";
    // See http://incubator.apache.org/jena/documentation/query/app_api.html
    Query query = QueryFactory.create(sparqlQueryString);
    QueryExecution qexec = QueryExecutionFactory.create(query, dataset);
    try {
        ResultSet results = qexec.execSelect();
        for (; results.hasNext(); ) {
            QuerySolution soln = results.nextSolution();
            int count = soln.getLiteral("count").getInt();
            System.out.println("count = " + count);
        }
    } finally {
        qexec.close();
    }
    // Close the dataset.
    dataset.close();
}

Example 20 with QuerySolution

use of org.apache.jena.query.QuerySolution in project jena by apache.

the class SelectBuilderTest method testVarReplacementInSubQuery.

@Test
public void testVarReplacementInSubQuery() throws ParseException {
    Model m = ModelFactory.createDefaultModel();
    Resource r = m.createResource("urn:one");
    m.add(r, m.getProperty("urn:p:one"), m.createTypedLiteral(1));
    m.add(r, m.getProperty("urn:p:two"), m.createTypedLiteral(3));
    m.add(r, m.getProperty("urn:p:three"), m.createTypedLiteral(5));
    r = m.createResource("urn:two");
    m.add(r, m.getProperty("urn:p:one"), m.createTypedLiteral(2));
    m.add(r, m.getProperty("urn:p:two"), m.createTypedLiteral(4));
    m.add(r, m.getProperty("urn:p:three"), m.createTypedLiteral(6));
    SelectBuilder sb = new SelectBuilder().addVar("?x").addVar("?p").addWhere("?x", "?p", "?o").addFilter("?o < ?limit");
    builder.addPrefix("xsd", XSD.getURI()).addVar("?x").addVar("count(?p)", "?c").addWhere("?x", "?p", "?o2").addSubQuery(sb).addGroupBy("?x");
    builder.setVar("?limit", 4);
    QueryExecution qexec = QueryExecutionFactory.create(builder.build(), m);
    ResultSet results = qexec.execSelect();
    assertTrue(results.hasNext());
    for (; results.hasNext(); ) {
        QuerySolution soln = results.nextSolution();
        assertTrue(soln.contains("x"));
        assertTrue(soln.contains("c"));
        if ("urn:one".equals(soln.get("?x").asResource().getURI())) {
            assertEquals(2, soln.get("?c").asLiteral().getInt());
        } else {
            assertEquals(1, soln.get("?c").asLiteral().getInt());
        }
    }
}