正则表达式：URL重写任何没有扩展名的路径

Question

I've written a regex which "works" for all the test cases I can think of. Essentially any URL which matches the pattern:

/app.* AND does not have an extension of length 1-4 at the end should be re-written. I've come up with:

/app((?:\\/[\\w([^\\..]{1,4}\b)\\-]+)+)

The question is, can this be simplified to achieve the same thing? Also, could I replace my use of \\w with something like .*, I could be wrong but I suspect as soon as I encounter a URL with an odd character it'll break.

EDIT 1: Example URLs that should match:

/app AND /app/
/app/auth
/app/auth/fb
/app/auth/twitter
/app/groups
/app/conn/manage
/app/play
/app/play/migrate
/app/play/migrate/done

Example URLs that should NOT match:

/app/js/some.file.js
/app/js/jquery.js
/app/styles/default/rain.css
/app/styles/name/file.css
/app/tpl/index.tpl
/app/tpl/file.html
/app/tpl/some.other.tpl

Thanks.

Answer 1

I think a better approach is to put all the assets you want the webserver to handle in a single directory. Like /app/public , so you would get app/public/js and app/public/html etc. This will make you have no edge cases and a far easier URL handling.

Anyway, I think the regex below answers the question you asked: match anything except if there is a extension with 1 - 4 characters on the file.

^(\/(\w+))*\/?(\.\w{5,})?\??([^.]+)?$

http://rubular.com/r/4CQ4amccH5

^              //start of anchor
  (
    \/         //match forward slash
    (\w+)      //match any word character, match atleast once 
  )+           //match this group atleast once (this group captures /app/etc/etc)
  \/?          //match a forward slash, make it optional (to also capture /app/)
  (\.\w{5,})?  //match any word after a . with 5 characters or more, make it optional
  \??          //match a ?, make the match optional
  ([^.]+)?     //match anything not containing a . 1 or more times, make the match optional
$              //end of anchor

This still needs some work to make it work in Java, mainly alot of escaping escape characters.

Answer 2

Your regex would be:

/app(/\w+)*/?$

I assumed you want to match a url with word characters that may end up with a slash but not a file extension.