RemoteQuery.java :  » Content-Management-System » contelligent » de » finix » contelligent » components » query » Java Open Source

/*
 * Copyright 2001-2006 C:1 Financial Services GmbH
 *
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License Version 2.1, as published by the Free Software Foundation.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
 */

package de.finix.contelligent.components.query;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.xmlio.in.DefaultSimpleImportHandler;
import org.apache.commons.xmlio.in.SimpleImporter;
import org.apache.commons.xmlio.in.SimplePath;
import org.apache.log4j.Logger;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import de.finix.contelligent.AbstractComponent;
import de.finix.contelligent.CallData;
import de.finix.contelligent.logging.LoggingService;

public class RemoteQuery extends AbstractComponent implements Query {
    final static private Logger log = LoggingService.getLogger(RemoteQuery.class);

    private String queryProvider;

    private int updateInterval;

    private long lastUpdate = 0;

    private List queryResult;

    /**
     * @return Returns the queryProvider.
     */
    public String getQueryProvider() {
        return queryProvider;
    }

    /**
     * @param queryProvider
     *            The queryProvider to set.
     */
    public void setQueryProvider(String queryProvider) {
        this.queryProvider = queryProvider;
    }

    /**
     * @return Returns the updateInterval.
     */
    public int getUpdateInterval() {
        return updateInterval;
    }

    /**
     * @param updateInterval
     *            The updateInterval to set.
     */
    public void setUpdateInterval(int updateInterval) {
        this.updateInterval = updateInterval;
    }

    public List getQueryResult(CallData callData) {
        long currentTimeMillis = System.currentTimeMillis();
        if ((currentTimeMillis - lastUpdate) / 1000 > updateInterval) {
            lastUpdate = currentTimeMillis;
            // Create an instance of HttpClient.
            HttpClient client = new HttpClient();
            // Create a method instance.
            GetMethod method = new GetMethod(queryProvider);
            queryResult = new ArrayList();
            try {
                // Execute the method.
                int statusCode = client.executeMethod(method);
                if (statusCode != HttpStatus.SC_OK) {
                    log.error("Failed to get remote query: " + method.getStatusLine());
                } else {
                    InputStream responseStream = method.getResponseBodyAsStream();
                    SimpleImporter importer = new SimpleImporter();
                    importer.setIncludeLeadingCDataIntoStartElementCallback(true);
                    importer.addSimpleImportHandler(new QueryResultParser(queryResult));
                    importer.parse(new InputSource(responseStream));
                }
            } catch (HttpException e) {
                log.error("Fatal protocol violation!", e);
            } catch (IOException e) {
                log.error("Fatal transport error!", e);
            } catch (ParserConfigurationException e) {
                log.error("Parser configuration failed!", e);
            } catch (SAXException e) {
                log.error("Exception while parsing provided query result!", e);
            } finally {
                // Release the connection.
                method.releaseConnection();
            }
        }
        return queryResult;
    }

    class QueryResultParser extends DefaultSimpleImportHandler {
        private List queryResult;

        private BasicQueryResult result;

        /**
         * @param queryResult
         */
        public QueryResultParser(List queryResult) {
            this.queryResult = queryResult;
        }

        public void startElement(SimplePath path, String name, AttributesImpl attributes, String leadingCDdata) {
            if (path.matches(QueryResultProvider.QUERY_RESULT_ELEMENT)) {
                result = new BasicQueryResult();
            } else if (path.matches(QueryResultProvider.QUERY_RESULT_ENTRY_ELEMENT)) {
                String key = attributes.getValue(QueryResultProvider.QUERY_RESULT_ENTRY_KEY_ATTRIBUTE);
                result.put(key, leadingCDdata);
            }
        }

        public void endElement(SimplePath path, String name) {
            if (path.matches(QueryResultProvider.QUERY_RESULT_ELEMENT)) {
                queryResult.add(result);
            }
        }
    }
}