Trivial patch follows. Might be not generic enough, but certainly an improvement in my case.
--- /tmp/olBiri_compile.el 2015-05-12 16:02:38.958969722 +0200
+++ lisp/progmodes/compile.el 2015-05-12 16:02:36.838967609 +0200
@@ -216,7 +216,7 @@ of[ \t]+\"?\\([a-zA-Z]?:?[^\":\n]+\\)\"?
;; due to matching filenames via \\(.*?\\). This might be faster.
(maven
;; Maven is a popular free software build tool for Java.
- "\\([^ \n]\\(?:[^\n :]\\| [^-/\n]\\|:[^ \n]\\)*?\\):\\[\\([0-9]+\\),\\([0-9]+\\)\\] " 1 2 3)
+ "\\(\\[WARNING\\] *\\)?\\([^ \n]\\(?:[^\n :]\\| [^-/\n]\\|:[^ \n]\\)*?\\):\\[\\([0-9]+\\),\\([0-9]+\\)\\] " 2 3 4 (1))
(jikes-line
"^ *\\([0-9]+\\)\\.[ \t]+.*\n +\\(<-*>\n\\*\\*\\* \\(?:Error\\|Warnin\\(g\\)\\)\\)"