/*
    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/servlets/base/AbstractServletBase.java,v 1.2 2006/03/18 19:14:48 hkollmann Exp $
    * $Revision: 1.2 $
    * $Date: 2006/03/18 19:14:48 $
    *
    * DbForms - a Rapid Application Development Framework
    * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
    *
    * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   */
  
  package org.dbforms.servlets.base;
  
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.util.Locale;
  
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import javax.servlet.ServletException;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.dbforms.servlets.Controller;
  import org.dbforms.util.MessageResources;
  import org.dbforms.util.MultipartRequest;
  import org.dbforms.util.ParseUtil;
  import org.dbforms.util.Util;
  
  /***
   * This is the abstract base class for generating reports.
   * 
   * @author Henner Kollmann
   */
  public abstract class AbstractServletBase extends HttpServlet {
     /*** logging category for this class */
     private static Log logCat        = LogFactory.getLog(Controller.class.getName());
  
     /*** 100KB default upload size */
     private int        maxUploadSize = 102400;
  
     /***
      * Basic servlet method, answers requests from the browser.
      * 
      * @param request
      *           HTTPServletRequest
      * @param response
      *           HTTPServletResponse
      * 
      * @throws ServletException
      *            if there is a servlet problem.
      * @throws IOException
      *            if there is an I/O problem.
      */
     public final void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        process_internal(request, response);
     }
  
     /***
      * Basic servlet method, answers requests fromt the browser.
      * 
      * @param request
      *           HTTPServletRequest
      * @param response
      *           HTTPServletResponse
      * 
      * @throws ServletException
      *            if there is a servlet problem.
      * @throws IOException
      *            if there is an I/O problem.
      */
     public final void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        process_internal(request, response);
     }
  
     /***
      * generates a report from request. Tries to get data from DbForms.
      * 
      * @param request
      *           HTTPServletRequest
      * @param response
      *           HTTPServletResponse
      */
     private final void process_internal(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
        // Verify if Locale have been setted in session with "LOCALE_KEY"
        // if not, take the request.getLocale() as default and put it in session
       // Verify if Locale have been setted in session with "LOCALE_KEY"
       // if not, take the request.getLocale() as default and put it in session
       processLocale(request);
 
       // create RFC-1867 data wrapper for the case the form was sent in
       // multipart mode
       // this is needed because common HttpServletRequestImpl - classes do not
       // support it
       // the whole application has to access Request via the "ParseUtil" class
       // this is also true for jsp files written by the user
       // #fixme taglib needed for convenient access to ParseUtil wrapper methods
       String contentType = request.getContentType();
 
       if (!Util.isNull(contentType) && contentType.startsWith("multipart")) {
          try {
             MultipartRequest multipartRequest = new MultipartRequest(request, maxUploadSize);
             request.setAttribute("multipartRequest", multipartRequest);
          } catch (IOException ioe) {
             logCat.error("::process - check if uploaded file(s) exceeded allowed size", ioe);
             sendErrorMessage("Check if uploaded file(s) exceeded allowed size.", response);
             return;
          }
       }
       process(request, response);
    }
 
    /***
     * generates a report from request. Tries to get data from DbForms.
     * 
     * @param request
     *           HTTPServletRequest
     * @param response
     *           HTTPServletResponse
     */
    abstract protected void process(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;
 
 
    /***
     * Initialize this servlet.
     * 
     * @exception ServletException
     *               if the initialization fails
     */
    public void init() throws ServletException {
       // if existing and valid, override default maxUploadSize, which determinates
       // how
       // big the http/multipart uploads may get
       String maxUploadSizeStr = this.getServletConfig().getInitParameter("maxUploadSize");
       if (!Util.isNull(maxUploadSizeStr)) {
          try {
             this.maxUploadSize = Integer.parseInt(maxUploadSizeStr);
          } catch (NumberFormatException nfe) {
             logCat.error("maxUploadSize not a valid number => using default.");
          }
       }
    }
 
    /***
     * Set the default locale
     * 
     * @param request
     *           the request object
     */
    private void processLocale(HttpServletRequest request) {
       String lang = ParseUtil.getParameter(request, "lang");
       String country = ParseUtil.getParameter(request, "country", "");
       Locale locale = null;
 
       if (!Util.isNull(lang)) {
          locale = new Locale(lang, country);
       } else if (MessageResources.getLocale(request) == null) {
          MessageResources.setLocale(request, request.getLocale());
       }
 
       if (locale != null) {
          MessageResources.setLocale(request, locale);
       }
    }
 
    /***
     * Send error messages to the servlet's output stream
     * 
     * @param message
     *           the message to display
     * @param response
     *           the response object
     */
    protected void sendErrorMessage(String message, HttpServletResponse response) {
       try {
          PrintWriter out = response.getWriter();
 
          response.setContentType("text/html");
          out.println("<html><body><h1>ERROR:</h1><p>");
          out.println(message);
          out.println("</p></body></html>");
       } catch (IOException ioe) {
          logCat.error("::sendErrorMessage - senderror message crashed", ioe);
       }
    }
 
 }