org.openrdf.repository.sparql.query.SPARQLBooleanQuery.java Source code

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Here is the source code for org.openrdf.repository.sparql.query.SPARQLBooleanQuery.java

Source

/*
 * Copyright Aduna (http://www.aduna-software.com/) (c) 2011.
 *
 * Licensed under the Aduna BSD-style license.
 */
package org.openrdf.repository.sparql.query;

import java.io.IOException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.openrdf.query.BooleanQuery;
import org.openrdf.query.QueryEvaluationException;
import org.openrdf.query.resultio.QueryResultParseException;
import org.openrdf.query.resultio.sparqlxml.SPARQLBooleanXMLParser;

/**
 * Parses boolean query response from remote stores.
 * 
 * @author James Leigh
 * 
 */
public class SPARQLBooleanQuery extends SPARQLQuery implements BooleanQuery {
    private SPARQLBooleanXMLParser parser = new SPARQLBooleanXMLParser();

    public SPARQLBooleanQuery(HttpClient client, String url, String base, String query) {
        super(client, url, base, query);
    }

    public boolean evaluate() throws QueryEvaluationException {
        try {
            boolean complete = false;
            HttpMethod response = getResponse();
            try {
                boolean result = parser.parse(response.getResponseBodyAsStream());
                complete = true;
                return result;
            } catch (HttpException e) {
                throw new QueryEvaluationException(e);
            } catch (QueryResultParseException e) {
                throw new QueryEvaluationException(e);
            } finally {
                if (!complete) {
                    response.abort();
                }
            }
        } catch (IOException e) {
            throw new QueryEvaluationException(e);
        }
    }

    @Override
    protected String getAccept() {
        return parser.getBooleanQueryResultFormat().getDefaultMIMEType();
    }
}