IndexerFactory.java

/*
 * ConcourseConnect
 * Copyright 2009 Concursive Corporation
 * http://www.concursive.com
 *
 * This file is part of ConcourseConnect, an open source social business
 * software and community platform.
 *
 * Concursive ConcourseConnect is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License as published
 * by the Free Software Foundation, version 3 of the License.
 *
 * Under the terms of the GNU Affero General Public License you must release the
 * complete source code for any application that uses any part of ConcourseConnect
 * (system header files and libraries used by the operating system are excluded).
 * These terms must be included in any work that has ConcourseConnect components.
 * If you are developing and distributing open source applications under the
 * GNU Affero General Public License, then you are free to use ConcourseConnect
 * under the GNU Affero General Public License.
 *
 * If you are deploying a web site in which users interact with any portion of
 * ConcourseConnect over a network, the complete source code changes must be made
 * available.  For example, include a link to the source archive directly from
 * your web site.
 *
 * For OEMs, ISVs, SIs and VARs who distribute ConcourseConnect with their
 * products, and do not license and distribute their source code under the GNU
 * Affero General Public License, Concursive provides a flexible commercial
 * license.
 *
 * To anyone in doubt, we recommend the commercial license. Our commercial license
 * is competitively priced and will eliminate any confusion about how
 * ConcourseConnect can be used and distributed.
 *
 * ConcourseConnect 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 Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with ConcourseConnect.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Attribution Notice: ConcourseConnect is an Original Work of software created
 * by Concursive Corporation
 */

package com.concursive.connect.indexer;

import com.concursive.connect.config.ApplicationPrefs;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author jfielek
 * @created Dec 15, 2008
 */
public class IndexerFactory {
  private static final Log LOG = LogFactory.getLog(IndexerFactory.class);
  private static String DEFAULT_INDEXER = "com.concursive.connect.indexer.LuceneIndexer";
  public final static IndexerFactory INSTANCE = new IndexerFactory();
  private static IIndexerService indexer = null;

  public static IndexerFactory getInstance() {
    return INSTANCE;
  }

  private IndexerFactory() {
    // nothing to do for this factory.
  }

  public synchronized void initializeIndexService(IndexerContext indexerContext) throws Exception {
    LOG.debug("initializeIndexService...");
    if (indexer == null) {
      IIndexerService newService = createIndexService(indexerContext.getApplicationPrefs());
      newService.setup(indexerContext);
      indexer = newService;
    }
  }

  private IIndexerService createIndexService(ApplicationPrefs prefs) throws Exception {
    // Determine the indexer service
    String indexerService = null;
    if (prefs != null) {
      indexerService = prefs.get("INDEXER.MODE");
    } else {
      LOG.error("ApplicationPrefs not defined...");
    }
    if (indexerService == null) {
      indexerService = DEFAULT_INDEXER;
    }
    LOG.info("Creating indexer service: " + indexerService);
    // Instantiate the indexer
    return instantiateIndexService(indexerService);
  }

  private IIndexerService instantiateIndexService(String indexerServiceClassName) {
    LOG.debug("Instantiating the index service: " + indexerServiceClassName);
    Class clazz = null;
    try {
      clazz = Class.forName(indexerServiceClassName);
    } catch (ClassNotFoundException e) {
      LOG.error("Specified indexer class not found", e);
      return null;
    }
    try {
      return (IIndexerService) clazz.newInstance();
    } catch (Exception e) {
      LOG.error("Could not instantiate indexer", e);
    }
    return null;
  }

  public IIndexerService getIndexerService() {
    return indexer;
  }
}