Trivial patch follows. Might be not generic enough, but certainly an
improvement in my case.

Paul

--- /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\\)\\)\\)"