You must differ between headless mode and headless jre. headless jre is stripped for all awt stuff while normal headless mode is allowed to use lightweight awt classes. lightweight awt does not need any os support (XServer,GDI). It works perfectly with with normal java under complete headless environment.
see
http://www.oracle.com/technetwork/ar...ss-136834.html
Only heavy components needs os support.
Maybe try to install java for arm yourself?