in web.xml you may declare your jsp file  as servlet  and assign a pattern to its url  mapping:

<servlet>
         <servlet-name>myIndex</servlet-name>
         <jsp-file>/app/index.jsp</jsp-file> 
</servlet>

<servlet-mapping>
       <servlet-name>myIndex</servlet-name>
       <url-pattern>/app/about</url-pattern>
</servlet-mapping>