Question

I’m using Spring 2.5 MVC and want to add another third-party Servlet. The Problem is, that Spring MVC catches all request, so the Servlet isn’t getting any request. Here a web.xml Snippet:

SpringMVC
org.springframework.web.servlet.DispatcherServlet
2

<servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>  

<servlet>
    <description>This is the servlet needed for cache.type servlet, returns the packed resources</description>
    <display-name>PackServlet</display-name>
    <servlet-name>PackServlet</servlet-name>
   <servlet-class>net.sf.packtag.servlet.PackServlet</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>PackServlet</servlet-name>
    <url-pattern>*.pack</url-pattern>
</servlet-mapping>

The /* mapping is really needed for the application, an pack:tag (the third-party Servlet) really need the mapping based on the file extension.
Any possiblities to tell Spring not to process the request?
Thanks and regards.

Answer 1

Actually you do not need spring to do anything, the servlet container can solve this for you.

When matching to which servlet a request is sent is dependent on the matching rules defined by the url-pattern. No 2 servlets may have the same pattern, but they may have overlapping patterns. Then 4 rules apply :

1) exact matches have priority over wildcard matches
2) longer path patterns have priority over shorter patterns
3) path matches have priority over filetype matches
4) / matches anything not already matched

<servlet-mapping>
  <servlet-name>PackServlet</servlet-name>
  <url-pattern>*.pack</url-pattern>
</servlet-mapping>
<servlet-mapping>
  <servlet-name>SpringMVC</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

If you use /* for the SpringMVC it may match on the longest path. By removing the * you are sure to follow the servlet spec for the default servlet and falls under rule 4.

Here you can find some more details.