compilation-error-regexp-alist syntax problems

[Roy Smith <roy@panix.com>]

I'm running ant as my M-X compile command, and trying to get next-error
to parse the output correctly.  The line I want to parse looks like:

    [javac] fileName:lineNumber: message

An example being:

    [javac] /Users/roy/Muse/sandbox.tip/src/SnmpBugDb/data/scripts/test/DataBaseTestCase.java:20: unreport\
ed exception java.io.IOException; must be caught or declared to be thrown

I've tried putting this in my .emacs file:

(add-hook 'compilation-mode-hook 'my-compilation-mode-hook t)
(defun my-compilation-mode-hook ()
  (setq compilation-error-regexp-alist
        (cons '("\\[javac\\] *\(/[^:]+\):\([^:]*\):" 1 2) compilation-error-regexp-alist)
        ))

but the regex doesn't match the line.  At this point, I think the problem is
that I can't figure out how many \'s I need to get the \( and \) to come
out properly in the final alist.

Can somebody set me straight?