ContentServlet.java

/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/help/branches/sakai-2.8.1/help-tool/src/java/org/sakaiproject/tool/help/ContentServlet.java $
 * $Id: ContentServlet.java 81373 2010-08-17 14:41:50Z stephen.marquard@uct.ac.za $
 ***********************************************************************************
 *
 * Copyright (c) 2003, 2004, 2005, 2006, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.osedu.org/licenses/ECL-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **********************************************************************************/

package org.sakaiproject.tool.help;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.URL;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.sakaiproject.api.app.help.HelpManager;
import org.sakaiproject.api.app.help.Resource;
import org.sakaiproject.component.cover.ComponentManager;

/**
 * Content Servlet serves help documents to document frame.
 * @version $Id: ContentServlet.java 81373 2010-08-17 14:41:50Z stephen.marquard@uct.ac.za $
 */
public class ContentServlet extends HttpServlet
{

  private static final long serialVersionUID = 1L;
	
  /** Our log (commons). */
  private static Log M_log = LogFactory.getLog(ContentServlet.class);

  private static final String DOC_ID = "docId";
  private static final String TEXT_HTML = "text/html; charset=UTF-8";
  private HelpManager helpManager;

  /**
   * @see javax.servlet.http.HttpServlet#doGet(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
   */
  protected void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

      getHelpManager().initialize();
      String docId = req.getParameter(DOC_ID);

      OutputStreamWriter writer = new OutputStreamWriter(res.getOutputStream(), "UTF-8");
      try {
          res.setContentType(TEXT_HTML);

          Resource resource = getHelpManager().getResourceByDocId(docId);

          URL url;
          if (resource != null)
          {
              if (!getHelpManager().getRestConfiguration().getOrganization()
                      .equalsIgnoreCase("sakai"))
              {
                  writer.write(RestContentProvider.getTransformedDocument(
                          getServletContext(), getHelpManager(), resource));
              } else {
                  if (resource.getLocation().startsWith("/"))
                  {
                      if (!"".equals(getHelpManager().getExternalLocation()))
                      {
                          url = new URL(getHelpManager().getExternalLocation()
                                  + resource.getLocation());
                      }
                      else
                      {
                          url = HelpManager.class.getResource(resource.getLocation());
                      }

                      if (url == null) {
                    	  M_log.warn("Help document " + docId + " not found at: " + resource.getLocation());
                      } else {
	                      BufferedReader br = new BufferedReader(
	                              new InputStreamReader(url.openStream(),"UTF-8"));
	                      try {
	                          String sbuf;
	                          while ((sbuf = br.readLine()) != null)
	                          {
	                              writer.write( sbuf );
	                              writer.write( System.getProperty("line.separator") );
	                          }
	                      } finally {
	                          br.close();
	                      }
                      }
                  }
                  else
                  {
                      res.sendRedirect(resource.getLocation());
                  }
              }
          } 
      } finally {
          try {
              writer.flush();
          } catch (IOException e) {
              // ignore
          }
          writer.close();
      }
  }

  /**
   * get the component manager through cover
   * @return help manager
   */
  public HelpManager getHelpManager()
  {
    if (helpManager == null)
    {
    	helpManager = (HelpManager) ComponentManager.get(HelpManager.class.getName()); 
    	return helpManager;
    }
    return helpManager;
  }
}