(when (load "dired-x" t)
  (defun jikes-compile (filename)
    (concat "jikes +E -bootclasspath /usr/local/java/jre/lib/rt.jar " filename))
  (add-to-list 'dired-guess-shell-alist-default
	       '("\\.java$" (jikes-compile nil)))
  (add-to-list 'dired-guess-shell-alist-default
	       '("\\.class$" "java ")))