JDEE

Jeffrey Phillips [jeffphil@gmail.com]

And if you want a graphical debugger, try JSwat http://jswat.sourceforge.net/ along with Nascif's JSwat.el
to integrate with JDEE found here http://www.emacswiki.org/cgi-bin/wiki/jswat.el. The JDEE listserv archives from last year has patches for JSwat.el to work with JSwat 3.0, since version on emacs wiki is for JSwat 2.0.