Java Code Examples for org.apache.jena.query.QuerySolution#varNames()

/**
 * Turns a QuerySolution into a Binding. 
 * @param map  the input QuerySolution
 * @return a Binding or null if the input is null
 */
public static Binding asBinding(final QuerySolution map) {
	if(map != null) {
		BindingHashMap result = new BindingHashMap();
		Iterator<String> varNames = map.varNames();
		while(varNames.hasNext()) {
			String varName = varNames.next();
			RDFNode node = map.get(varName);
			if(node != null) {
				result.add(Var.alloc(varName), node.asNode());
			}
		}
		return result;
	}
	else {
		return null;
	}
}
 

@Override
public Object invokeFunction(String functionName, QuerySolution bindings) throws javax.script.ScriptException, java.lang.NoSuchMethodException {
	List<String> functionParams = getFunctionParameters(functionName);
	Object[] params = new Object[functionParams.size()];
	Iterator<String> varNames = bindings.varNames();
	while(varNames.hasNext()) {
		String varName = varNames.next();
		int index = functionParams.indexOf(varName);
		if(index < 0) {
			index = functionParams.indexOf("$" + varName);
		}
		if(index >= 0) {
			RDFNode value = bindings.get(varName);
			if(value != null) {
				params[index] = JSFactory.asJSTerm(value.asNode());
			}
		}
	}
	return invokeFunctionOrdered(functionName, params);
}
 

public static Binding createBinding(QuerySolution sol) {
	final BindingMap binding = BindingFactory.create();
	for (Iterator<String> it = sol.varNames(); it.hasNext();) {
		final String varName = it.next();
		binding.add(VarUtils.allocVar(varName), sol.get(varName).asNode());
	}
	return binding;
}
 

public static List<Var> getVariables(
        final QuerySolution sol) {
    final List<Var> variables = new ArrayList<>();
    for (Iterator<String> it = sol.varNames(); it.hasNext();) {
        variables.add(allocVar(it.next()));
    }
    return variables;
}
 

public static Binding getBinding(
        final QuerySolution sol) {
    final BindingMap binding = BindingFactory.create();
    for (Iterator<String> it = sol.varNames(); it.hasNext();) {
        String varName = it.next();
        binding.add(allocVar(varName), sol.get(varName).asNode());
    }
    return binding;
}
 

public static QueryExecution createQueryExecution(Query query, Dataset dataset, QuerySolution bindings) {
	if(USE_TRANSFORM && bindings != null) {
		Map<Var,Node> substitutions = new HashMap<Var,Node>();
		Iterator<String> varNames = bindings.varNames();
		while(varNames.hasNext()) {
			String varName = varNames.next();
			substitutions.put(Var.alloc(varName), bindings.get(varName).asNode());
		}
		Query newQuery = JenaUtil.queryWithSubstitutions(query, substitutions);
		return ARQFactory.get().createQueryExecution(newQuery, dataset);
	}
	else {
		return ARQFactory.get().createQueryExecution(query, dataset, bindings);
	}
}
 

/**
 * Overriding Original search method to implement Quepy's two step requests for
 * QA
 */
@Override
public void search(IQuestion question, String language) throws Exception {
	String questionString;
	if (!question.getLanguageToQuestion().containsKey(language)) {
		return;
	}
	questionString = question.getLanguageToQuestion().get(language);
	log.debug(this.getClass().getSimpleName() + ": " + questionString);
	this.getParamMap().put(this.getQueryKey(), questionString);
	if (this.setLangPar) {
		this.getParamMap().put(this.getLangKey(), language);
	}
	HttpResponse response = this.getIsPostReq() ? fetchPostResponse(getUrl(), getParamMap())
			: fetchGetResponse(getUrl(), getParamMap());
	// Test if error occured
	if (response.getStatusLine().getStatusCode() >= 400) {
		throw new Exception("QUEPY Server could not answer due to: " + response.getStatusLine());
	}
	// Fetch the SPARQL
	String sparqlStr = null;
	JSONParser parser = new JSONParser();

	JSONObject responsejson = (JSONObject) parser.parse(responseparser.responseToString(response));
	JSONArray queriesArr = (JSONArray) responsejson.get("queries");
	for (int i = 0; i < queriesArr.size(); i++) {
		JSONObject queryObj = (JSONObject) queriesArr.get(i);
		if (queryObj.get("language").toString().equalsIgnoreCase("sparql") && queryObj.get("query") != null) {
			sparqlStr = queryObj.get("query").toString();
			break;
		}
	}
	if (sparqlStr != null) {
		HashSet<String> result = new HashSet<String>();
		question.setSparqlQuery(sparqlStr);
		// Fetch results using sparql
		Query query = QueryFactory.create(sparqlStr);
		// Remote execution.
		QueryExecution qexec = QueryExecutionFactory.sparqlService(SPARQL_ENDPOINT, query);
		// Set the DBpedia specific timeout.
		((QueryEngineHTTP) qexec).addParam("timeout", "10000");
		// Execute.
		ResultSet rs = qexec.execSelect();
		// Get the values and push them to the question
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			Iterator<String> varIt = qs.varNames();
			while (varIt.hasNext()) {
				RDFNode node = qs.get(varIt.next());
				result.add(node.asLiteral().getString());
			}
		}
		question.setGoldenAnswers(result);
	}
}