Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2000-2011 Regents of the University of California and the

 *              National Center for Ecological Analysis and Synthesis

 *

 *   '$Author: leinfelder $'

 *     '$Date: 2012-11-29 16:52:29 -0800 (Thu, 29 Nov 2012) $'

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

package edu.ucsb.nceas.metacat.index;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStreamWriter;

import java.io.Writer;

import java.sql.SQLException;

import java.util.Hashtable;

import java.util.Set;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.io.IOUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.apache.solr.client.solrj.SolrServerException;

import org.apache.solr.common.params.ModifiableSolrParams;

import org.apache.solr.common.params.SolrParams;

import org.apache.solr.servlet.SolrRequestParsers;

import org.dataone.service.exceptions.NotFound;

import org.dataone.service.exceptions.NotImplemented;

import org.dataone.service.exceptions.UnsupportedType;

import org.dataone.service.types.v1.Subject;

import org.xml.sax.SAXException;

import edu.ucsb.nceas.metacat.DBTransform;

import edu.ucsb.nceas.metacat.common.query.SolrQueryResponseWriterFactory;

import edu.ucsb.nceas.metacat.common.query.SolrQueryService;

import edu.ucsb.nceas.metacat.common.query.SolrQueryServiceController;

import edu.ucsb.nceas.metacat.common.query.stream.ContentTypeByteArrayInputStream;

import edu.ucsb.nceas.utilities.PropertyNotFoundException;

/**

 * This class will query the solr server and return the result.

 * @author tao

 *

 */

public class MetacatSolrIndex {

    //public static final String SOLRQUERY = "solr";

    //public static final String SOLR_HOME_PROPERTY_NAME = "solr.homeDir";

    //public static final String SOLR_CONFIG_FILE_NAME_PROPERTY_NAME = "solr.configFileName";

    //public static final String SOLR_COLLECTION_NAME_PROPERTY_NAME = "solr.collectionName";

    //public static final String SOLR_SERVER_CLASSNAME_PROPERTY_NAME = "solr.server.classname";

    private static Log log = LogFactory.getLog(MetacatSolrIndex.class);

    private static MetacatSolrIndex  solrIndex = null;

    public static MetacatSolrIndex getInstance() throws Exception {

        if (solrIndex == null) {

            solrIndex = new MetacatSolrIndex();

        }

        return solrIndex;

    }

    /**

     * Constructor

     * @throws SAXException 

     * @throws IOException 

     * @throws ParserConfigurationException 

     */

    private MetacatSolrIndex() throws Exception {

    }

    /**

     * Query the solr server

     * @param query  the solr query

     * @param authorizedSubjects the authorized subjects in this query session

     * @return the result as the InputStream

     * @throws SolrServerException 

     * @throws ClassNotFoundException 

     * @throws SQLException 

     * @throws PropertyNotFoundException 

     * @throws SAXException 

     * @throws ParserConfigurationException 

     * @throws UnsupportedType 

     * @throws NotFound 

     * @throws NotImplemented 

     */

    public InputStream query(String query, Set<Subject>authorizedSubjects) throws SolrServerException, IOException, PropertyNotFoundException, SQLException, 

    ClassNotFoundException, ParserConfigurationException, SAXException, NotImplemented, NotFound, UnsupportedType {

        if(authorizedSubjects == null || authorizedSubjects.isEmpty()) {

            throw new SolrServerException("MetacatSolrIndex.query - There is no any authorized subjects(even the public user) in this query session.");

        }

        InputStream inputStream = null;

        SolrParams solrParams = SolrRequestParsers.parseQueryString(query);

        String wt = solrParams.get(SolrQueryService.WT);

        // handle normal and skin-based queries

        if (SolrQueryService.isSupportedWT(wt)) {

            // just handle as normal solr query

            inputStream = SolrQueryServiceController.getInstance().query(solrParams, authorizedSubjects);

        }

        else {

            // assume it is a skin name

            String qformat = wt;

            // perform the solr query using wt=XML

            wt = SolrQueryResponseWriterFactory.XML;

            ModifiableSolrParams msp = new ModifiableSolrParams(solrParams);

            msp.set(SolrQueryService.WT, wt);

            inputStream = SolrQueryServiceController.getInstance().query(msp, authorizedSubjects);

            // apply the stylesheet (XML->HTML)

            DBTransform transformer = new DBTransform();

            String documentContent = IOUtils.toString(inputStream, "UTF-8");

            String sourceType = "solr";

            String targetType = "-//W3C//HTML//EN";

            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            Writer writer = new OutputStreamWriter(baos , "UTF-8");

            // TODO: include more params?

            Hashtable<String, String[]> params = new Hashtable<String, String[]>();

            params.put("qformat", new String[] {qformat});

            transformer.transformXMLDocument(

                    documentContent , 

                    sourceType, 

                    targetType , 

                    qformat, 

                    writer, 

                    params, 

                    null //sessionid

                    );

            // finally, get the HTML back

            inputStream = new ContentTypeByteArrayInputStream(baos.toByteArray());

            ((ContentTypeByteArrayInputStream) inputStream).setContentType("text/html");

        }

        return inputStream;

    }

}