JumpersFilter


1   /*
2   
3   This software is OSI Certified Open Source Software.
4   OSI Certified is a certification mark of the Open Source Initiative.
5   
6   The license (Mozilla version 1.0) can be read at the MMBase site.
7   See http://www.MMBase.org/license
8   
9   */
10  package org.mmbase.servlet;
11  
12  import javax.servlet.*;
13  import javax.servlet.http.*;
14  import java.net.URI  ;
15  import java.net.URISyntaxException  ;
16  import org.mmbase.module.builders.Jumpers;
17  import org.mmbase.module.core.*;
18  import org.mmbase.util.logging.*;
19  
20  /**
21   * Redirects request based on information supplied by the jumpers builder.
22   *
23   * @application Tools, Jumpers
24   * @author Jaco de Groot
25   * @version $Id: JumpersFilter.java,v 1.16 2006/06/27 14:36:58 johannes Exp $
26   */
27  public class JumpersFilter implements Filter, MMBaseStarter {
28      private static final Logger log = Logging.getLoggerInstance(JumpersFilter.class);
29      private static MMBase mmbase;
30      private static Jumpers jumpers;
31      private static String   name;
32  
33      private Thread   initThread;
34  
35      /**
36       * Supported for use with older versions of the servlet api, such as used by Orion 1.5.2
37       * This method simply thows an exception when called.
38       * @deprecated will be dropped in future versions
39       */
40      public void setFilterConfig(FilterConfig fc) {
41          log.info("Setting filter-config");        
42          throw new UnsupportedOperationException  ("This method is not part of the Servlet api 2.3");
43      }
44  
45      /**
46       * Supported for use with older versions of the servlet api, such as used by Orion 1.5.2
47       * This method simply thows an exception when called.
48       * @deprecated will be dropped in future versions
49       */
50      public FilterConfig getFilterConfig() {
51          log.info("Getting filter-config");        
52          throw new UnsupportedOperationException  ("This method is not part of the Servlet api 2.3");
53      }
54  
55      public MMBase getMMBase() {
56          return mmbase;
57      }
58  
59      public void setMMBase(MMBase mmb) {
60          mmbase = mmb;
61      }
62  
63      public void setInitException(ServletException se) {
64          // never mind, simply, ignore
65      }
66  
67      /**
68       * Initializes the filter
69       */
70      public void init(javax.servlet.FilterConfig   filterConfig) throws ServletException {
71          log.info("Starting JumpersFilter with " + filterConfig);
72          name = filterConfig.getFilterName();
73          MMBaseContext.init(filterConfig.getServletContext());
74          MMBaseContext.initHtmlRoot();
75          // stuff that can take indefinite amount of time (database down and so on) is done in separate thread
76          initThread = new MMBaseStartThread(this);
77          initThread.start();
78      }
79  
80      /**
81       * Filters the request: tries to find a jumper and redirects to this url when found, otherwise the 
82       * request will be handled somewhere else in the filterchain.
83       * @param servletRequest The ServletRequest.
84       * @param servletResponse The ServletResponse.
85       * @param filterChain The FilterChain.
86       */
87      public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws java.io.IOException  , ServletException {
88          if (mmbase == null) {
89              filterChain.doFilter(servletRequest, servletResponse);
90              return;
91          }
92          if (jumpers == null) {
93              if (mmbase != null) {
94                  jumpers = (Jumpers)mmbase.getBuilder("jumpers");
95              } 
96              if (jumpers == null) {
97                  filterChain.doFilter(servletRequest, servletResponse);
98                  return; // nothing to be done
99              }
100         }
101         HttpServletRequest req = (HttpServletRequest)servletRequest;
102         HttpServletResponse res = (HttpServletResponse)servletResponse;
103         /*
104          * getContextPath()
105          * Returns the portion of the request URI that indicates the context of the request.
106          * The context path always comes first in a request URI.
107          * The path starts with a "/" character but does not end with a "/" character.
108          * For servlets in the default (root) context, this method returns "". The container does not decode this string.
109          */
110         String   context = "";
111         context = req.getContextPath();
112         int contextPart = context.length();
113         String   reqURI = req.getRequestURI();
114         String   key = "";
115         if (contextPart < reqURI.length()) {
116             // also remove the leading "/", unless it's an empty string.
117             key = req.getRequestURI().substring(contextPart+1);
118         }
119 
120         if (log.isDebugEnabled()) {
121             log.debug("contextpath is: " + context);
122             log.debug("key is: " + key);
123             log.debug("uri is: " + reqURI);
124         }
125         
126         //ignore keys with extensions
127         if (key.indexOf('.') == -1 ) {
128             // because Tomcat version > 5.0.5 always adds a trailing slash if
129             // there's a directory with the same name, the trailing slash must be removed
130             if (key.endsWith("/")) {
131                 key = key.substring(0,key.length()-1);
132                 if (log.isDebugEnabled()){
133                     log.debug("after removing trailing slash key becomes: " + key);
134                 }
135             }
136             //get jumper from Jumpers builder
137             String   url = jumpers.getJump(key);
138             if (url != null) {
139                 /*
140                  * Sends a temporary redirect response to the client using the specified redirect location URL.
141                  * This method can accept relative URLs; the servlet container must convert the relative URL
142                  * to an absolute URL before sending the response to the client. If the location is relative without a leading '/' the
143                  * container interprets it as relative to the current request URI. If the location is relative with a leading '/' the container
144                  *  interprets it as relative to the servlet container root.
145                  * If the response has already been committed, this method throws an IllegalStateException.
146                  *  After using this method, the response should be considered to be committed and should not be written to.
147                  */
148                 // res.sendRedirect(res.encodeRedirectURL(req.getContextPath() + url));
149 
150                 // there can be different types of jumper uris which all must behandled
151                 // differently:
152                 // - absolute with a scheme (http://www.servername.nl/context/bla/bla123), muste be redirected
153                 // - absolute without a scheme (/bla/bla123), must be redirected
154                 // - relative (bla/bla123), must be made absolute and then be redirected
155                 URI   redirURI = null;
156                 try {
157                     redirURI = new URI  (url);
158                 } catch (URISyntaxException   ex) {
159                     log.error ("jumper URI syntax is not valid");
160                 }
161                 if (redirURI != null) {
162                     if (redirURI.isAbsolute()) {
163                         res.sendRedirect(url);
164                     } else if (url.startsWith("/")) {
165                         res.sendRedirect(url);
166                     } else {
167                         res.sendRedirect(context +"/" + url);
168                     }
169                 }
170                 return;
171             }
172         }
173         
174         filterChain.doFilter(servletRequest, servletResponse);
175     }
176 
177     /**
178      * destroys the filter
179      */
180     public void destroy() {
181         log.info("Filter " + name + " destroyed.");
182         initThread.interrupt();
183     }
184 
185 
186 }
187
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Free Books Free Magazines
Popular Tags