/**
    * This file Copyright (c) 2003-2014 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.cms.servlets;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  
  /**
   * The servlet gets a {@link MVCServletHandler} with the method
   * {@link #getHandler(HttpServletRequest, HttpServletResponse)}.
   * {@link MVCServletHandler#getCommand()} is called and the returned command name is passed to the
   * {@link MVCServletHandler#execute(String)} method wich returns the view name. Finally it calls
   * {@link MVCServletHandler#renderHtml(String)} passing the view name.
   * <p>
   * Make a subclass to provide you own handler(s).
   * @version $Id$
   */
  public abstract class MVCServlet extends HttpServlet {
  
      /**
       * Stable serialVersionUID.
       */
      private static final long serialVersionUID = 222L;
  
      private static Logger log = LoggerFactory.getLogger(MVCServlet.class);
  
      /**
       * @see HttpServlet#doGet(HttpServletRequest,HttpServletResponse)
       */
      @Override
      protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
          doPost(request, response);
      }
  
      /**
       * @see HttpServlet#doPost(HttpServletRequest, HttpServletResponse)
       */
      @Override
      protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
          IOException {
  
          // http://issues.apache.org/bugzilla/show_bug.cgi?id=22666
          //
          // 1. The Coyote HTTP/1.1 connector has a useBodyEncodingForURI attribute which
          // if set to true will use the request body encoding to decode the URI query
          // parameters.
          // - The default value is true for TC4 (breaks spec but gives consistent
          // behaviour across TC4 versions)
          // - The default value is false for TC5 (spec compliant but there may be
          // migration issues for some apps)
          // 2. The Coyote HTTP/1.1 connector has a URIEncoding attribute which defaults to
          // ISO-8859-1.
          // 3. The parameters class (o.a.t.u.http.Parameters) has a QueryStringEncoding
          // field which defaults to the URIEncoding. It must be set before the parameters
          // are parsed to have an effect.
          //
          // Things to note regarding the servlet API:
          // 1. HttpServletRequest.setCharacterEncoding() normally only applies to the
          // request body NOT the URI.
          // 2. HttpServletRequest.getPathInfo() is decoded by the web container.
          // 3. HttpServletRequest.getRequestURI() is not decoded by container.
         //
         // Other tips:
         // 1. Use POST with forms to return parameters as the parameters are then part of
         // the request body.
 
         // this can throw an exception in jetty
         try {
             request.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
         }
         catch (java.lang.IllegalStateException e) {
             log.error("can't set character encoding for the request", e); //$NON-NLS-1$
         }
 
         MVCServletHandler handler = getHandler(request, response);
 
         if (handler == null) {
             log.warn("no handler found for url {}", request.getRequestURI()); //$NON-NLS-1$
             response.sendError(404);
             return;
         }
 
         // why do i have to change it if request was setted? But i have to!
         response.setCharacterEncoding("UTF-8"); //$NON-NLS-1$
 
         String command = handler.getCommand();
         String view = handler.execute(command);
         handler.renderHtml(view);
     }
 
     /**
      * @param request
      * @return
      */
     protected abstract MVCServletHandler getHandler(HttpServletRequest request, HttpServletResponse response);
 }