/* 
    P/P   *  Method: void net.sourceforge.pebble.web.filter.TransformingFilter()
          */
     1  /*
     2   * Copyright (c) 2003-2006, Simon Brown
     3   * All rights reserved.
     4   *
     5   * Redistribution and use in source and binary forms, with or without
     6   * modification, are permitted provided that the following conditions are met:
     7   *
     8   *   - Redistributions of source code must retain the above copyright
     9   *     notice, this list of conditions and the following disclaimer.
    10   *
    11   *   - Redistributions in binary form must reproduce the above copyright
    12   *     notice, this list of conditions and the following disclaimer in
    13   *     the documentation and/or other materials provided with the
    14   *     distribution.
    15   *
    16   *   - Neither the name of Pebble nor the names of its contributors may
    17   *     be used to endorse or promote products derived from this software
    18   *     without specific prior written permission.
    19   *
    20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    30   * POSSIBILITY OF SUCH DAMAGE.
    31   */
    32  package net.sourceforge.pebble.web.filter;
    33  
    34  import net.sourceforge.pebble.Constants;
    35  import net.sourceforge.pebble.domain.AbstractBlog;
    36  import net.sourceforge.pebble.domain.Blog;
    37  import net.sourceforge.pebble.domain.BlogManager;
    38  import net.sourceforge.pebble.domain.MultiBlog;
    39  import org.apache.commons.logging.Log;
    40  import org.apache.commons.logging.LogFactory;
    41  
    42  import javax.servlet.*;
    43  import javax.servlet.http.HttpServletRequest;
    44  import java.io.IOException;
    45  import java.net.URLDecoder;
    46  
    47  /**
    48   * A filter that transforms an incoming URI into an action URI.
    49   *
    50   * @author    Simon Brown
    51   */
    52  public class TransformingFilter implements Filter {
    53  
    54    /** the config of this filter */
    55    private FilterConfig filterConfig;
    56  
    57    /** the log used by this class */
    58    private static Log log = LogFactory.getLog(TransformingFilter.class);
    59  
    60    /**
    61     * Initialises this instance.
    62     *
    63     * @param config    a FilterConfig instance
    64     */
           /* 
    P/P     *  Method: void init(FilterConfig)
            * 
            *  Postconditions:
            *    this.filterConfig == config
            *    init'ed(this.filterConfig)
            */
    65    public void init(FilterConfig config) {
    66      this.filterConfig = config;
    67    }
    68  
    69    /**
    70     * Called when this filter is taken out of service.
    71     */
           /* 
    P/P     *  Method: void destroy()
            */
    72    public void destroy() {
    73    }
    74  
    75    /**
    76     * Contains the processing associated with this filter.
    77     */
    78    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    79        throws ServletException, IOException {
    80  
    81      HttpServletRequest httpRequest = (HttpServletRequest)request;
    82      AbstractBlog blog = (AbstractBlog)request.getAttribute(Constants.BLOG_KEY);
    83  
    84      // get URI and strip off the context (e.g. /blog)
    85      String uri = httpRequest.getRequestURI();
    86      uri = uri.substring(httpRequest.getContextPath().length(), uri.length());
    87  
    88      // now we're left with a URI
    89      if (BlogManager.getInstance().isMultiBlog()) {
    90        if (uri.length() == 0) {
    91          uri = "/";
    92        }
    93        int index = uri.indexOf("/", 1);
    94        if (index == -1) {
    95          index = uri.length();
    96        }
    97        String blogName = uri.substring(1, index);
    98        blogName = URLDecoder.decode(blogName, "UTF-8");
    99        if (BlogManager.getInstance().hasBlog(blogName)) {
   100          uri = uri.substring(index, uri.length());
   101        }
   102      }
   103  
   104      if (uri == null || uri.trim().equals("")) {
   105        uri = "/";
   106      }
   107      log.trace("uri : " + uri);
   108  
   109      if (httpRequest.getQueryString() != null) {
   110        uri += "?" + httpRequest.getQueryString();
   111      }
   112      httpRequest.setAttribute(Constants.EXTERNAL_URI, uri);
   113  
   114      UriTransformer transformer = new UriTransformer();
   115      String internalUri;
   116  
   117      if (blog instanceof Blog) {
   118        internalUri = transformer.getUri(uri, (Blog)blog);
   119      } else {
   120        internalUri = transformer.getUri(uri, (MultiBlog)blog);
   121      }
   122  
   123      request.setAttribute(Constants.INTERNAL_URI, internalUri);
   124  
   125      log.trace(uri + " -> " + internalUri);
   126  
   127      chain.doFilter(request, response);
   128    }
   129  
   130  }