Getting a HeadlessException: No X11 DISPLAY variable was set

Question

Exception in thread \"main\" java.awt.HeadlessException:
    No X11 DISPLAY variable was set, but this program performed an operation which requires it.
        at j         


        

Answer 1

This appears to be a more general SWING/AWT/JDK problem that just the JBOSS installer:

The accepted answer below solved the issue for me :

Unable to run java gui programs with ubuntu

("sudo apt-get install openjdk-6-jdk")