The url-pattern element of a servlet-mapping associates a servlet with a set of URLs. When a request arrives, the container uses a simple procedure for matching the URL in the request with a url-pattern
The url-pattern specification:
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 context path and the path info is null.
All other strings are used for exact matches only.
All the wild cards mentioned in the url-pattern will be virtual, there is no need that they have to exist in the physical file system.
In your case if your servlet is placed in the location com.company.servlet with the name TestServlet then it's upto you how you want frame url's so that this servlet resource will be accessed.
<url-pattern> /Beer/* </url-pattern>
There is no need that directory with name Beer should exist, it's a virtual mapping to your servlet to protect from external world for direct access and map it through any virtual url's using <url-pattern>