JAMWikiFilter.java :  » Wiki-Engine » gwtwiki » org » jamwiki » servlets » Java Open Source

/**
 * Licensed under the GNU LESSER GENERAL PUBLIC LICENSE, version 2.1, dated February 1999.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the latest version of the GNU Lesser General
 * Public License as published by the Free Software Foundation;
 *
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program (LICENSE.txt); if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package org.jamwiki.servlets;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.jamwiki.WikiBase;
import org.jamwiki.utils.WikiLogger;
import org.jamwiki.utils.WikiUtil;

/**
 * Perform filtering of all Wiki page requests, including setting the character
 * encoding to UTF-8 and verifying that no setup or upgrade is required.
 */
public class JAMWikiFilter implements Filter {

  private static final WikiLogger logger = WikiLogger
      .getLogger(JAMWikiFilter.class.getName());
  private String encoding = "UTF-8";
  private FilterConfig config = null;

  /**
   * Standard servlet filter destroy() method implementation.
   */
  public void destroy() {
  }

  /**
   * Perform standard processing required by all servlets including setting
   * request encoding to UTF-8. See http://wiki.apache.org/tomcat/Tomcat/UTF-8
   * for a further discussion.
   */
  public void doFilter(ServletRequest request, ServletResponse response,
      FilterChain chain) throws IOException, ServletException {
    request.setCharacterEncoding("UTF-8");
    if (WikiUtil.WEBAPP_CONTEXT_PATH == null
        && request instanceof HttpServletRequest) {
      WikiUtil.WEBAPP_CONTEXT_PATH = ((HttpServletRequest) request)
          .getContextPath();
    }
    if (redirectNeeded(request, response)) {
      return;
    }
    chain.doFilter(request, response);
  }

  /**
   * Standard servlet filter init() method implementation.
   */
  public void init(FilterConfig config) throws ServletException {
    this.encoding = config.getInitParameter("encoding");
    this.config = config;
  }

  /**
   *
   */
  private void redirect(HttpServletRequest request,
      HttpServletResponse response, String url) throws IOException,
      ServletException {
    response.sendRedirect(response.encodeRedirectURL(url));
  }

  /**
   *
   */
  private boolean redirectNeeded(ServletRequest servletRequest,
      ServletResponse servletResponse) throws IOException, ServletException {
    if (!(servletRequest instanceof HttpServletRequest)
        || !(servletResponse instanceof HttpServletResponse)) {
      return false;
    }
    HttpServletRequest request = (HttpServletRequest) servletRequest;
    HttpServletResponse response = (HttpServletResponse) servletResponse;
    if (redirectSetup(request)) {
      // redirect to setup page
      String url = request.getContextPath() + "/" + WikiBase.DEFAULT_VWIKI
          + "/Special:Setup";
      redirect(request, response, url);
      return true;
    }
    if (redirectUpgrade(request)) {
      // redirect to upgrade page
      String url = request.getContextPath() + "/" + WikiBase.DEFAULT_VWIKI
          + "/Special:Upgrade";
      redirect(request, response, url);
      return true;
    }
    return false;
  }

  /**
   * Determine whether or not to redirect to the setup page.
   */
  private boolean redirectSetup(HttpServletRequest request) {
    if (!WikiUtil.isFirstUse()) {
      return false;
    }
    if (request.getRequestURI().toLowerCase().endsWith(".css")) {
      return false;
    }
    if (ServletUtil.isTopic(request, "Special:Setup")) {
      return false;
    }
    if (ServletUtil.isTopic(request, "jsp/setup.jsp")) {
      return false;
    }
    return true;
  }

  /**
   * Determine whether or not to redirect to the upgrade page.
   */
  private boolean redirectUpgrade(HttpServletRequest request) {
    if (!WikiUtil.isUpgrade()) {
      return false;
    }
    if (request.getRequestURI().toLowerCase().endsWith(".css")) {
      return false;
    }
    if (ServletUtil.isTopic(request, "Special:Upgrade")) {
      return false;
    }
    if (ServletUtil.isTopic(request, "Special:Login")) {
      return false;
    }
    if (ServletUtil.isTopic(request, "jsp/upgrade.jsp")) {
      return false;
    }
    return true;
  }
}