Metacat

/**

 *  Copyright: 2013 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *

 * 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.common.query;

import java.io.IOException;

import java.io.InputStream;

import java.net.MalformedURLException;

import java.util.Map;

import java.util.Set;

import javax.xml.parsers.ParserConfigurationException;

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

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

import org.apache.solr.client.solrj.embedded.EmbeddedSolrServer;

import org.apache.solr.client.solrj.impl.CommonsHttpSolrServer;

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

import org.apache.solr.core.CoreContainer;

import org.apache.solr.schema.IndexSchema;

import org.apache.solr.schema.SchemaField;

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.common.SolrServerFactory;

/**

 * A class to handle the solr query. It will call the SolrServerFactory to generate a SolrServer and

 * determine the type - the embedded or http solr server.

 * @author tao

 *

 */

public class SolrQueryServiceController {

    private static SolrQueryServiceController controller = null;

    private boolean isEmbeddedSolrServer = false;

    private EmbeddedSolrQueryService embeddedQueryService = null;

    private HttpSolrQueryService httpQueryService = null;

    /*

     * Private consctructor

     */

    private SolrQueryServiceController() throws UnsupportedType, ParserConfigurationException, IOException, SAXException, NotFound {

        SolrServer solrServer = SolrServerFactory.createSolrServer();

        if(solrServer instanceof EmbeddedSolrServer) {

            isEmbeddedSolrServer = true;

            EmbeddedSolrServer embeddedServer = (EmbeddedSolrServer) solrServer;

            CoreContainer coreContainer = SolrServerFactory.getCoreContainer();

            String collectionName = SolrServerFactory.getCollectionName();

            embeddedQueryService = new EmbeddedSolrQueryService(embeddedServer, coreContainer, collectionName);

        } else {

            isEmbeddedSolrServer = false;

            CommonsHttpSolrServer httpServer = (CommonsHttpSolrServer)solrServer;

            httpQueryService = new HttpSolrQueryService(httpServer);

        }

    }

    /**

     * Get the controller

     * @return

     * @throws UnsupportedType

     * @throws NotFound

     * @throws ParserConfigurationException

     * @throws IOException

     * @throws SAXException

     */

    public static SolrQueryServiceController getInstance() throws UnsupportedType, NotFound, ParserConfigurationException, IOException, SAXException {

        if(controller == null) {

            controller = new SolrQueryServiceController();

        }

        return controller;

    }

    /**

     * Query the Solr server with specified query string or SolrParams and the user's identity. 

     * @param query  query string. It is for the HttpSolrQueryService.

     * @param params the SolrParam. It is for the EmbeddedSolrQueryService.

     * @param subjects

     * @return

     * @throws NotImplemented

     * @throws NotFound

     * @throws IOException

     * @throws SolrServerException 

     * @throws SAXException 

     * @throws ParserConfigurationException 

     * @throws UnsupportedType 

     */

    public InputStream query(SolrParams params,Set<Subject>subjects) throws NotImplemented, NotFound, IOException, UnsupportedType, ParserConfigurationException, SAXException, SolrServerException  {

        if(isEmbeddedSolrServer) {

            return embeddedQueryService.query(params, subjects);

        } else {

            return httpQueryService.query(params, subjects);

        }

    }

    /**

     * Get the spec version of the solr server

     * @return

     */

    public String getSolrSpecVersion() {

        if(isEmbeddedSolrServer) {

            return embeddedQueryService.getSolrServerVersion();

        } else {

            return httpQueryService.getSolrServerVersion();

        }

    }

    /**

     * Get the fields list of the index schema

     * @return

     * @throws SAXException 

     * @throws IOException 

     * @throws ParserConfigurationException 

     * @throws MalformedURLException 

     * @throws Exception

     */

    public  Map<String, SchemaField> getIndexSchemaFields() throws MalformedURLException, ParserConfigurationException, IOException, SAXException  {

        if(isEmbeddedSolrServer) {

            return embeddedQueryService.getIndexSchemaFields();

        } else {

            return httpQueryService.getIndexSchemaFields();

        }

    }

    /**

     * Access the SOLR index schema

     * @return

     * @throws SAXException 

     * @throws IOException 

     * @throws ParserConfigurationException 

     * @throws MalformedURLException 

     */

    public IndexSchema getSchema() throws MalformedURLException, ParserConfigurationException, IOException, SAXException {

        if(isEmbeddedSolrServer) {

            return embeddedQueryService.getSchema();

        } else{

            return httpQueryService.getSchema();

        }

    }

}