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

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

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/*
 * 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 java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpMethod;
import org.openrdf.query.QueryEvaluationException;
import org.openrdf.query.TupleQuery;
import org.openrdf.query.TupleQueryResult;
import org.openrdf.query.TupleQueryResultHandler;
import org.openrdf.query.TupleQueryResultHandlerException;
import org.openrdf.query.impl.TupleQueryResultImpl;
import org.openrdf.query.resultio.QueryResultParseException;
import org.openrdf.query.resultio.sparqlxml.SPARQLResultsXMLParser;

/**
 * Parses tuple results in the background.
 * 
 * @author James Leigh
 * 
 */
public class SPARQLTupleQuery extends SPARQLQuery implements TupleQuery {
    private SPARQLResultsXMLParser parser = new SPARQLResultsXMLParser();

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

    public TupleQueryResult evaluate() throws QueryEvaluationException {
        try {
            BackgroundTupleResult result = null;
            HttpMethod response = getResponse();
            try {
                InputStream in = response.getResponseBodyAsStream();
                result = new BackgroundTupleResult(parser, in, response);
                execute(result);
                InsertBindingSetCursor cursor = new InsertBindingSetCursor(result, getBindings());
                List<String> list = new ArrayList<String>(result.getBindingNames());
                list.addAll(getBindingNames());
                return new TupleQueryResultImpl(list, cursor);
            } catch (HttpException e) {
                throw new QueryEvaluationException(e);
            } finally {
                if (result == null) {
                    response.abort();
                }
            }
        } catch (IOException e) {
            throw new QueryEvaluationException(e);
        }
    }

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

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