How static resource is served by glassfish server without servlet-mapping

Question

I deployed war file with some static resource (.zip) on glassfish server @ physical location {WebAppRoot}/resources/WebFiles/zippedFiles/{FileName}.zip so for downloading/accessing file from browser relative path or URI will be {domain.com}/resources/WebFiles/zippedFiles/{FileName}.zip.Someday before i am trying to enable resume support for downloading such files after some Googleing i come to know that i have to tell glassfish that .zip file is an static content,so after adding

<servlet-mapping>
   <servlet-name>DefaultServlet</servlet-name>
   <url-pattern>.zip</url-pattern>
</servlet-mapping>

Resume support is enabled.

So my question is,Before adding <servlet-mapping> how the .zip file is served? Is that file handled by DispatcherServlet (Dynamic content)? How the server knows URI({domain.com}/resources/WebFiles/zippedFiles/{FileName}.zip) is of an file not the controller or JSP (view) for which DispatcherServlet is resposible.

And one last what is benefit of adding such <servlet-mapping>?

Answer 1

There is a 'default servlet' that handles all unmapped resources.