Metacat

/**

 *  '$RCSfile$'

 *  Copyright: 2005 University of New Mexico and the 

 *             Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *   '$Author: costa $'

 *     '$Date: 2006-06-14 08:44:17 -0700 (Wed, 14 Jun 2006) $'

 * '$Revision: 3011 $'

 *

 * 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.advancedsearch;

import java.io.File;

import java.io.IOException;

import javax.servlet.RequestDispatcher;

import javax.servlet.ServletConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import edu.ucsb.nceas.metacat.client.*;

import edu.ucsb.nceas.utilities.Options;

/** 

 * @author dcosta

 * 

 * The BrowseServlet class executes a browse action. This is equivalent to

 * a simple search, but the user clicks on a link to determine the search term.

 */

public class BrowseServlet extends HttpServlet {

  /*

   * Class fields

   */

  private static final String CONFIG_DIR = "WEB-INF";

  private static final String CONFIG_NAME = "metacat.properties";

  static final long serialVersionUID = 0;  // Needed for Eclipse warning.

  // Instance Variables

  private String contextString = "";

  // Methods

  /**

   * Executes a browse-based simple search.

   */

  public void doPost(HttpServletRequest request, HttpServletResponse response)

      throws IOException, ServletException {

    AdvancedSearch advancedSearch;

    String browseValue;

    RequestDispatcher dispatcher;

    HttpSession httpSession = request.getSession();

    Metacat metacat = (Metacat) httpSession.getAttribute("metacat");

    MetacatHelper metacatHelper = new MetacatHelper();

    String metacatURL;

    String qformat = (String) httpSession.getAttribute("qformat");

    String result = "";

    final String resultsJSP = metacatHelper.getResultsJSP();

    ServletContext servletContext = httpSession.getServletContext();

    String xslPath = metacatHelper.getResultsetXSL(request);

    // First check whether the metacat URL was set as a context-param.

    metacatURL = servletContext.getInitParameter("metacatURL");

    // If no metacat URL was configured, then derive the metacat URL from the

    // server name and server port.

    if (metacatURL == null || metacatURL.equals("")) {

      String serverName = request.getServerName();

      int serverPort = request.getServerPort();

      metacatURL = 

    	 metacatHelper.constructMetacatURL(serverName, serverPort, contextString);

    }

    // Tell the web server that the response is HTML

    response.setContentType("text/html");

    // Fetch the browseValue parameter from the request and execute a search

    advancedSearch = new AdvancedSearch(null);

    browseValue = request.getParameter("browseValue");

    result = advancedSearch.executeSearch(metacatURL, metacat, qformat,

                                          xslPath, browseValue);

    // Store the result HTML string in the request for retrieval by

    // the metacatpathqueryresults.jsp form.

    request.setAttribute("result", result);

    dispatcher = request.getRequestDispatcher(resultsJSP);

    dispatcher.forward(request, response);

  }

  /**

   * Initializes the servlet. Reads properties and initializes object fields.

   * 

   * @throws ServletException

   */

  public void init(ServletConfig config) throws ServletException {

	ServletContext context = null;

    String dirPath;

    Options options = null;

    super.init(config);

    context = config.getServletContext();

    dirPath = context.getRealPath(CONFIG_DIR);

    File propertyFile = new File(dirPath, CONFIG_NAME);

    try {

      options = Options.initialize(propertyFile);

    }

    catch (IOException e) {

      System.err.println("Error in loading options: " + e.getMessage());

    }

    this.contextString = options.getOption("context");

  }

}