How to get WebLogic to process certain files as JSP

I am migrating a java web application from OC4J to WebLogic 11g. The application contains the following servlet mapping:

<servlet-mapping>
    <servlet-name>jsp</servlet-name>
    <url-pattern>*_dyn.txt</url-pattern>
</servlet-mapping>

This works in OC4J for two reasons:

- the servlet name "jsp" is automatically mapped to the JSP servlet

- OC4J accepts the pattern *_dyn.txt even though it does not conform with the servlet standard.

I discovered in WebLogic I can explicitly map the servlet name "jsp" to the JSP servlet by adding the following:

<servlet>
    <servlet-name>jsp</servlet-name>
    <servlet-class>weblogic.servlet.JSPServlet</servlet-class>
</servlet>

This works if I use a standard URL pattern such as /dyn/* but not the non-standard URL pattern *_dyn.txt that was accepted by OC4J.

I have tried using Tuckey's UrlRewriteFilter to map it instead, but this results in an exception in the JSPServlet class.

My UrlRewriteFilter rule looks like this:

<rule match-type="wildcard">
    <from>**/*_dyn.*</from>
    <run class="weblogic.servlet.JSPServlet" method="service" />
</rule>

The exception I get is this:

Error 500--Internal Server Error 
[AddToMap: pattern=/bla/test_dyn.txt class=jsp_servlet._bla.__test_dyn_txt]
    at weblogic.servlet.JSPServlet.service(JSPServlet.java:220)
    at开发者_如何学Go javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.tuckey.web.filters.urlrewrite.Run.invokeRunMethod(Run.java:416)

Can anyone tell me how I can achieve my goal?

Thanks

Martin