Does javax.swing need X11 on Unix?

[sakcee]

Hi

this question might as well be that "does OS needs processor to run "
but anyway

Does javax.swing needs X11 on the unix platform? I have a machine
which havs just barebone Unix with no windowing system and although
the calls to javax.swing.UIMangere is in catch all block, it still
crashes that it "Can't connect to X11 window server using".

what I am wondering is that how can it trick the catch all , and does
swing needs windowing system to run.

thanks

 

[Tom Hawtin]

Does javax.swing needs X11 on the unix platform? I have a machine
which havs just barebone Unix with no windowing system and although
the calls to javax.swing.UIMangere is in catch all block, it still
crashes that it "Can't connect to X11 window server using".

Are you expecting it to do some ASCII art?

Sun's AWT X implementation requires X "client" libraries: xlib. I'm not
entirely sure of the exact details. You will also need to have the
DISPLAY environment variable pointing to a working X Server. The X
Server need not be on the same machine, but you need to be able to
connect to it. For instance, I sometimes run Java programs on my Ubuntu
machine, but displaying on my Vista laptop.

You don't technically need a desktop environment (e.g. KDE, GNOME, RoX)
or even a window manager (e.g. metacity, sawfish, fvwm, twm) (although
you wont get window frames, unless you explicitly get Swing (the PL&F)
to draw them).

Older versions also required the Motif library. I think for 1.5 this is
the default on Solaris but not on Linux (google for AWT_TOOLKIT).

Tom Hawtin

 

[Matt Humphrey]

| (e-mail address removed) wrote:
| >
| > Does javax.swing needs X11 on the unix platform? I have a machine
| > which havs just barebone Unix with no windowing system and although
| > the calls to javax.swing.UIMangere is in catch all block, it still
| > crashes that it "Can't connect to X11 window server using".
|
| Are you expecting it to do some ASCII art?
|
| Sun's AWT X implementation requires X "client" libraries: xlib. I'm not
| entirely sure of the exact details. You will also need to have the
| DISPLAY environment variable pointing to a working X Server. The X
| Server need not be on the same machine, but you need to be able to
| connect to it. For instance, I sometimes run Java programs on my Ubuntu
| machine, but displaying on my Vista laptop.
|
| You don't technically need a desktop environment (e.g. KDE, GNOME, RoX)
| or even a window manager (e.g. metacity, sawfish, fvwm, twm) (although
| you wont get window frames, unless you explicitly get Swing (the PL&F)
| to draw them).
|
| Older versions also required the Motif library. I think for 1.5 this is
| the default on Solaris but not on Linux (google for AWT_TOOLKIT).

Also, if you just want to run Java without a display at all and are trying
to get around any GUI or Font requirements, look into Xvfb--X virtual frame
buffer. It gives you an X Server that you can direct Java to, but does not
actually display anything. I've used this when I've had servlets doing
headless rendering, but that was quite a number of years ago--there may be
better techniques available now.

Cheers,
Matt Humphrey (e-mail address removed) http://www.iviz.com/

 

[Daniel Pitts]

(e-mail address removed) wrote:

| >
| > Does javax.swing needs X11 on the unix platform? I have a machine
| > which havs just barebone Unix with no windowing system and although
| > the calls to javax.swing.UIMangere is in catch all block, it still
| > crashes that it "Can't connect to X11 window server using".
|
| Are you expecting it to do some ASCII art?
|
| Sun's AWT X implementation requires X "client" libraries: xlib. I'm not
| entirely sure of the exact details. You will also need to have the
| DISPLAY environment variable pointing to a working X Server. The X
| Server need not be on the same machine, but you need to be able to
| connect to it. For instance, I sometimes run Java programs on my Ubuntu
| machine, but displaying on my Vista laptop.
|
| You don't technically need a desktop environment (e.g. KDE, GNOME, RoX)
| or even a window manager (e.g. metacity, sawfish, fvwm, twm) (although
| you wont get window frames, unless you explicitly get Swing (the PL&F)
| to draw them).
|
| Older versions also required the Motif library. I think for 1.5 this is
| the default on Solaris but not on Linux (google for AWT_TOOLKIT).

Also, if you just want to run Java without a display at all and are trying
to get around any GUI or Font requirements, look into Xvfb--X virtual frame
buffer. It gives you an X Server that you can direct Java to, but does not
actually display anything. I've used this when I've had servlets doing
headless rendering, but that was quite a number of years ago--there may be
better techniques available now.

Cheers,
Matt Humphrey (e-mail address removed)://www.iviz.com/

You can start Java in headless mode too. There are a lot of operations
you CAN do in headless mode.

 

[Tom Hawtin]

You can start Java in headless mode too. There are a lot of operations
you CAN do in headless mode.

Prior to 1.4 you needed xvfb on Unix machines without access to real X
Servers. Windows machines don't have this problem.


Headless AWT support from 1.4:

http://java.sun.com/j2se/1.4.2/docs/guide/awt/AWTChanges.html#headless


Tom Hawtin