Is there an open source library that, given ...
/a/b/c
/a/b/c/d/e
would return ../..
or for that matter given
/a/b/c/d
/a/b/c/e
would return ../d
?
If you don't mind passing by converting your Strings into URI then this latter one has the method relativize which should do exactly what you want, take a look here.