Question:"no route found to match"

Rails
1

in my routes.rb, I have such url
map.file ':user/:file
it works well with following url:

  1. jay/web
  2. jay/web2
    but it encounters error with:
    jay/web2.0
    it displays : no route found to match “/post/web2.o” with
    {:method=>:get}
    I guess it is because the char ‘.’ and rails can not translate it
    exactly.
    How can I　fix it ?
    thank you
    zico