How to use java String.matches(str) method in Velocity Templates

Question

I'm attempting to do a match on the user agent in velocity templates.

$ua does print out but Matches! does not. What am I doing wrong?

#set( $ua = $request.getHeader('User-Agent'))
<p>$ua</p>
#if( $ua.matches('/Windows.(NT|XP|ME|9)/')) 
<p>Matches!</p>
#end

Answer 1

I know this is old, but the solution to this problem is that the regex provided to matches must match the ENTIRE string in order to return true. So, for example:

$ua.matches('Windows.(NT|XP|ME|9)')

returns false, but

$ua.matches('.*Windows.(NT|XP|ME|9).*')

will behave as you expect, returning true if Windows.(...) is in the string.

This is a bit odd and really stymied me for a while today.

PS - no slashes are required in the regex!