Can I exclude some concrete urls from url-pattern inside filter-mapping

Question

I want some concrete filter to be applied for all urls except for one concrete  i e  for    except for  specialpath    Is there a possibility to do that     sample code    lt filter gt       lt filter-name gt SomeFilter lt  filter-name gt       lt filter-class gt org somproject AFilter lt  filter-class gt   lt  filter gt   lt filter-mapping gt       lt filter-name gt SomeFilter lt  filter-name gt       lt url-pattern gt    lt  url-pattern gt     lt  -- the question is  how to modify this line   -- gt       lt dispatcher gt REQUEST lt  dispatcher gt       lt dispatcher gt FORWARD lt  dispatcher gt   lt  filter-mapping gt

User · Answer

I used an approach described by Eric Daugherty: I created a special servlet that always answers with 403 code and put its mapping before the general one.

Mapping fragment:

  <servlet>
    <servlet-name>generalServlet</servlet-name>
    <servlet-class>project.servlet.GeneralServlet</servlet-class>
  </servlet>
 <servlet>
    <servlet-name>specialServlet</servlet-name>
    <servlet-class>project.servlet.SpecialServlet</servlet-class>
 </servlet>
 <servlet-mapping>
    <servlet-name>specialServlet</servlet-name>
    <url-pattern>/resources/restricted/*</url-pattern>
 </servlet-mapping>
 <servlet-mapping>
    <servlet-name>generalServlet</servlet-name>
    <url-pattern>/resources/*</url-pattern>
 </servlet-mapping>

And the servlet class:

public class SpecialServlet extends HttpServlet {
    public SpecialServlet() {
        super();
    }
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.sendError(HttpServletResponse.SC_FORBIDDEN);
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.sendError(HttpServletResponse.SC_FORBIDDEN);
    }
}

User · Answer

I have encounterd the same issue  but I find a anwser showing below   web xml    lt  -- set this param value for the filter-- gt       lt init-param gt               lt param-name gt freePages lt  param-name gt               lt param-value gt              MainFrame jsp               lt  param-value gt       lt  init-param gt    filter java  strFreePages   config getInitParameter  freePages      get the exclue pattern from config file isFreePage strRequestPage     decide the exclude path   this way you don t have to harass the concrete Filter class

User · Answer

The standard Servlet API doesn t support this facility  You may want either to use a rewrite-URL filter for this like Tuckey s one  which is much similar Apache HTTPD s mod rewrite   or to add a check in the doFilter   method of the Filter listening on     String path     HttpServletRequest  request  getRequestURI    if  path startsWith  quot  specialpath  quot          chain doFilter request  response      Just continue chain    else          Do your business stuff here for all paths other than  specialpath     You can if necessary specify the paths-to-be-ignored as an init-param of the filter so that you can control it in the web xml anyway  You can get it in the filter as follows  private String pathToBeIgnored   public void init FilterConfig config        pathToBeIgnored   config getInitParameter  quot pathToBeIgnored quot       If the filter is part of 3rd party API and thus you can t modify it  then map it on a more specific url-pattern  e g   otherfilterpath   and create a new filter on    which forwards to the path matching the 3rd party filter  String path     HttpServletRequest  request  getRequestURI    if  path startsWith  quot  specialpath  quot          chain doFilter request  response      Just continue chain    else       request getRequestDispatcher  quot  otherfilterpath quot    path  forward request  response      To avoid that this filter will call itself in an infinite loop you need to let it listen  dispatch  on REQUEST only and the 3rd party filter on FORWARD only  See also   How to prevent static resources from being handled by front controller servlet which is mapped on    How to handle static content in Spring MVC

User · Answer

I was able to handle this in Spring 2 as following  private boolean isInPath ServletRequest request       String PATH TO VALIDATE    quot  path  quot      String path     HttpServletRequest  request  getRequestURI       return path    null  amp  amp  path toLowerCase   contains PATH TO VALIDATE

User · Answer

This approach works when you want to prevent a certain filter and all the following ones  It should work well if you eg  want to serve some content as static resources within your servlet container instead of letting your application logic  through a filter like GuiceFilter    Map the folder with your static resource files to the default servlet  Create a servlet filter and put it before the GuiceFilter in your web xml  In your created filter  you can separate between forwarding some requests to the GuiceFilter and others directly to the dispatcher  Example follows     web xml   lt servlet-mapping gt       lt servlet-name gt default lt  servlet-name gt       lt url-pattern gt  static   lt  url-pattern gt   lt  servlet-mapping gt    lt filter gt       lt filter-name gt StaticResourceFilter lt  filter-name gt       lt filter-class gt com project filter StaticResourceFilter lt  filter-class gt   lt  filter gt   lt filter-mapping gt       lt filter-name gt StaticResourceFilter lt  filter-name gt       lt url-pattern gt  static   lt  url-pattern gt   lt  filter-mapping gt    lt filter gt       lt filter-name gt guiceFilter lt  filter-name gt       lt filter-class gt com google inject servlet GuiceFilter lt  filter-class gt   lt  filter gt   lt filter-mapping gt       lt filter-name gt guiceFilter lt  filter-name gt       lt url-pattern gt    lt  url-pattern gt   lt  filter-mapping gt    StaticResourceFilter class  public class StaticResourceFilter implements Filter        private final static Logger LOGGER   LoggerFactory getLogger StaticResourceFilter class        private static final String RESOURCE PATH     static         Override     public void init final FilterConfig filterConfig  throws ServletException           LOGGER info  StaticResourceFilter initialized                Override     public void doFilter final ServletRequest request  final ServletResponse response                           final FilterChain chain  throws IOException  ServletException            String path     HttpServletRequest  request  getServletPath            if  path toLowerCase   startsWith RESOURCE PATH                 request getRequestDispatcher path  forward request  response             else               chain doFilter request  response                         Override     public void destroy             LOGGER info  StaticResourceFilter destroyed              Unfortunately if you just want to skip a single step in the filter chain while keeping those that follows  this will not work

User · Answer

I also Had to filter based on the URL pattern   servicename  api stats  in java code    if  path startsWith    servicename  api statistics       validatingAuthToken   HttpServletRequest  request  getHeader  auth token     filterChain doFilter request  response                   But its bizarre  that servlet doesn t support url pattern other than       This should be a very common case for servlet API s

User · Answer

If for any reason you cannot change the original filter mapping       in my case   and you are dispatching to an unchangeable third-party filter  you can find useful the following    Intercept the path to be bypassed Skip to and execute the last ring of the filter chain  the servlet itself  The skipping is done via reflection  inspecting the container instances in debug mode    The following works in Weblogic 12 1 3          import org apache commons lang3 reflect FieldUtils        import javax servlet Filter                       Override          public void doFilter ServletRequest request  ServletRespons response  FilterChain chain  throws IOException  ServletException              String path     HttpServletRequest  request  getRequestURI               if  bypassSWA path                  swpFilterHandler doFilter request  response  chain                else                 try                       Filter   FieldUtils readField                                   FieldUtils readField                                           FieldUtils readField chain   filters   true     last   true     item   true                       doFilter request  response  chain                   catch  IllegalAccessException e                      e printStackTrace

User · Answer

I don t think you can  the only other configuration alternative is to enumerate the paths that you want to be filtered  so instead of    you could add some for  this   and  that   etc  but that won t lead to a sufficient solution when you have alot of those paths   What you can do is add a parameter to the filter providing an expression  like a regular expression  which is used to skip the filter functionality for the paths matched  The servlet container will still call your filter for those url s but you will have better control over the configuration   Edit  Now that you mention you have no control over the filter  what you could do is either inherit from that filter calling super methods in its methods except when the url path you want to skip is present and follow the filter chain like  BalusC proposed  or build a filter which instantiates your filter and delegates under the same circumstances  In both cases the filter parameters would include both the expression parameter you add and those of the filter you inherit from or delegate to   The advantage of building a delegating filter  a wrapper  is that you can add the filter class of the wrapped filter as parameter and reuse it in other situations like this one

[java] Can I exclude some concrete urls from <url-pattern> inside <filter-mapping>?

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