If you’ve ever had to use a Java app within a tiling window manager like dwm,
you’ve probably come across AWT_TOOLKIT=MToolkit. As dwm’s man page
elegantly puts it, using this environment variable instructs Java to use an
older toolkit to “fix” issues with grey windows and other oddly behaved GUI
elements as a result of using XAWT.
However, in my experience, using MToolkit also produces inconsistencies, so thankfully another method also exists: wmname. Stumbling across this utility within the Problems with Java page of awesome’s wiki (and within their mailing list) this tool seems to fix the aforementioned problems.
Just download and compile the tiny app and have it launch within your .xinitrc
as so:
wmname LG3D &
and Java apps should be working as normal again!