java without X11?

[Scott Mitchell]

On Fri, May 05, 2006 at 10:35:35AM -0300, Fernan Aguero wrote:
> +----[ Scott Mitchell <scott+lists.freebsd at fishballoon.org> (04.May.2006 18:45):
> | 
> | The java binary in diablo-1.5.0_06 doesn't have a load-time dependency on
> | libX11.so or any other X11 libraries, nor libawt.so - I guess the JVM will
> | dlopen() libawt.so if it needs to do any graphical stuff.  As proof of
> | concept a simple "Hello, World" Java program compiles and runs just fine on
> | a machine with no X11 libraries installed.  I expect any program that
> | didn't use AWT/Swing would work just as well.
> 
> Great, that was what I was about to do once I could get
> hands on this box.
> 
> So, this means that I could safely ignore the warnings about missing
> dependencies (upon package installation)?

I believe so, as long as your Java program really doesn't need X11...
 
> | Interestingly libawt.so doesn't have any direct X11 dependencies either,
> | rather it depends on libmawt.so, of which several different versions exist,
> | in the jre/lib/i386/{xawt,motif21,headless} directories.  The xawt and
> | motif21 versions depend on various X11 libraries, but the headless version
> | does not.  It looks like setting the java.awt.headless property to true or
> | just having no $DISPLAY will cause the headless libraries to be used.  You
> | should be able to use AWT/Swing classes in any way that doesn't require
> | access to a real display - so loading any manipulating images should work,
> | but trying to say open a window will throw a HeadlessException.
 
> OK, good to know.
> 
> thanks for your reply,

Glad I could help.

Cheers,

	Scott

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