Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A Class that tracks sessions for MetaCatServlet users.

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

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Matt Jones

 *

 *   '$Author$'

 *     '$Date$'

 * '$Revision$'

 *

 * 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;

import java.util.TimerTask;

import org.apache.log4j.Logger;

/**

 *  QueryResutlTableBuilder is class to build xml_queryresult table during metacat initialization.

 *  xml_querytable is a db table to store query returnfiled value. It is a cache of resultset and 

 *  peformance optimization approach to replace xml_index and xml_node tables.  In metacat 1.8.0,

 *  xml_queryresult table is built during the first time of query hitting metacat. So first time search

 *  will take longer time since this search involves xml_index and xml_node tables.  In order to

 *  decrease the first query search time, this class will build the xml_querytable during the metacat

 *  intialization base on some metacat common clients' query , e.g. kepler, morpho, esa, knb, nceas,

 *  sanparks' regestiry.

 */

public class QueryResultTableBuilder extends TimerTask

{

	private String[] docidList = null;

	private String[] returnFieldList = null;

	private Logger logMetacat = Logger.getLogger(QueryResultTableBuilder.class);

	/**

	 * Default the constructor.  It will get doc id list from current xml_table

	 *

	 */

	QueryResultTableBuilder()

	{

		 docidList = getDocListFromXMLDocumentTables();

		 returnFieldList = getReturnFieldList();

	}

	/**

	 *  Constructor with given docid list

	 * @param docList  list of docid

	 */

	 QueryResultTableBuilder(String[] docList)

	 {

		 docidList = docList;

		 returnFieldList = getReturnFieldList();

	 }

	 /**

	  * Builds the result table base on the given docid list and returnfields

	  */

	public void run()

	{

		buildQueryResultTable();

	}

	/*

	 * Build query result table.

	 */

	private void buildQueryResultTable()

	{

		if (docidList != null && returnFieldList != null )

		{

		}

		else

		{

			logMetacat.warn("There is no doc list or returnfFieldList. We wouldn't build queryresult table ");

		}

	}

	/*

	 * Gets return document list array from xml_documents table.

	 */

	private String[] getDocListFromXMLDocumentTables()

	{

		String[] returnDocList = null;

		return returnDocList;

	}

	/*

	 * Gets common return fields list from metacat.properties file.

	 */

	private String[] getReturnFieldList()

	{

		String[] returnField = null;

		return returnField;

	}

}