wildcard in servlet/filter url-pattern mapping

From servlet specification,

SRV.11.2 Specification of Mappings

In theWeb application deployment descriptor, the following syntax is used to define
mappings:
• A string beginning with a ‘/’ character and ending with a ‘/*’ suffix is used
for path mapping.
• A string beginning with a ‘*.’ prefix is used as an extension mapping.
• A string containing only the ’/’ character indicates the "default" servlet of
the application. In this case the servlet path is the request URI minus the con-
text path and the path info is null.
• All other strings are used for exact matches only.

This means Wildcard asterisk can only be used in two cases

 1. at the end of a pattern, like /*

  2. pattern *.extension matches any file name ending with extension

To match two urls  

/r2/v1/clientjoin  and 

/r2/v1/clientleave to a filter,

 r2/v1/client* won't work.

Instead, defining two url-pattern for the filter mapping solves the problem.

        <filter-mapping>

           <filter-name> BasicAuthFilter</filter-name >

           <url-pattern> /r2/v1/clientjoin </url-pattern>

           <url-pattern> /r2/v1/clientleave </url-pattern>

        </filter-mapping>

Detailed xml schema can be found from http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd and http://java.sun.com/xml/ns/javaee/web-common_3_0.xsd