Examples with BooleanQueryResultParser org.eclipse.rdf4j.query.resultio.BooleanQueryResultParser used on opensource projects

Example 1 with BooleanQueryResultParser

use of org.eclipse.rdf4j.query.resultio.BooleanQueryResultParser in project rdf4j by eclipse.

the class SPARQLProtocolSession method getBoolean.

/**
 * Parse the response in this thread using a suitable {@link BooleanQueryResultParser}. All HTTP
 * connections are closed and released in this method
 *
 * @throws RDF4JException
 */
protected boolean getBoolean(HttpUriRequest method) throws IOException, RDF4JException {
    // Specify which formats we support using Accept headers
    Set<QueryResultFormat> booleanFormats = BooleanQueryResultParserRegistry.getInstance().getKeys();
    if (booleanFormats.isEmpty()) {
        throw new RepositoryException("No boolean query result parsers have been registered");
    }
    // send the tuple query
    HttpResponse response = sendBooleanQueryViaHttp(method, booleanFormats);
    try {
        // if we get here, HTTP code is 200
        String mimeType = getResponseMIMEType(response);
        try {
            QueryResultFormat format = BooleanQueryResultFormat.matchMIMEType(mimeType, booleanFormats).orElseThrow(() -> new RepositoryException("Server responded with an unsupported file format: " + mimeType));
            BooleanQueryResultParser parser = QueryResultIO.createBooleanParser(format);
            QueryResultCollector results = new QueryResultCollector();
            parser.setQueryResultHandler(results);
            parser.parseQueryResult(response.getEntity().getContent());
            return results.getBoolean();
        } catch (QueryResultParseException e) {
            throw new RepositoryException("Malformed query result from server", e);
        }
    } finally {
        EntityUtils.consumeQuietly(response.getEntity());
    }
}