Min. ports needed for headless AWT/Swing

Wed Jul 1 11:58:29 UTC 2020

Van: Aryeh Friedman <aryeh.friedman at gmail.com>
Datum: woensdag, 1 juli 2020 13:33
Aan: Ronald Klop <ronald-lists at klop.ws>
CC: freebsd-java at freebsd.org, Michael Osipov <1983-01-06 at gmx.net>
Onderwerp: Re: Min. ports needed for headless AWT/Swing
> 
>  
>  
> On Wed, Jul 1, 2020 at 5:52 AM Ronald Klop <ronald-lists at klop.ws> wrote:
>> 
>> Van: Aryeh Friedman <aryeh.friedman at gmail.com>
>> Datum: maandag, 29 juni 2020 20:59
>> Aan: Michael Osipov <1983-01-06 at gmx.net>
>> CC: freebsd-java at freebsd.org
>> Onderwerp: Re: Min. ports needed for headless AWT/Swing
>>> 
>>> On Mon, Jun 29, 2020 at 2:28 PM Michael Osipov <1983-01-06 at gmx.net> wrote:
>>> 
>>> > Am 2020-06-29 um 17:43 schrieb Aryeh Friedman:
>>> > > I have a java application that works fine with setenv DISPLAY :0.0 on my
>>> > > desktop FreeBSD 12.1 (amd64) [with Xfce4] but when I attempt to run the
>>> > > same app on a VM that has the minimum ports needed to install OpenJDK 8
>>> > and
>>> > > Tomcat I get an exception saying that it can't connect to the X server
>>> > even
>>> > > though I did setenv DISPLAY desktop:0.0 (and xhost + on the desktop).
>>> > > Note it is the same user on both machines (NIS/NFS password DB/home dirs)
>>> > > doing the running on both machines but is a different user then the one
>>> > > logged in at the console (I do all my development in a separate account)
>>> >
>>> > Are you look for "-Djava.awt.headless=true"?
>>> >
>>> 
>>> Since this is a screen capture/recording program (which I am the developer)
>>> I need to be able to capture the console (running X) that I am currently
>>> on.   So the question is what is the minimum set of ports/packages I need
>>> to install on the VM to make it see and X server?   It should be noted the
>>> program has no GUI but does use java.awt.Robot#createScreenCapture (using
>>> the full screen resolution as it's bounds) individual frames of the longer
>>> video.
>>> 
>>> Here is the specific exception I am attempting to fix:
>>> On desktop (192.168.11.20)
>>> % xhost +
>>> 
>>> On VM (192.168.11.4):
>>> % setenv DISPLAY 192.168.11.20:0.0
>>> % java
>>> -javaagent:/usr/local/share/java/classes/jacocoagent.jar=destfile=/usr/home/aryeh/fnwe-scap-1a1.C036/jacoco.exec,jmx=true,excludes=thistest/*:test/*
>>> -cp
>>> /usr/home/aryeh/fnwe-scap-1a1.C036/scrap/www/WEB-INF/lib/fnwe-scap-1a1.jar:/usr/local/share/java/classes/thisTest.jar:/usr/local/share/java/classes/pcCommon.jar:/usr/local/share/java/classes/pcUtil.jar
>>> test.TestMain
>>> 
>>> Result of the jvm invocation on the VM (not it works no problem su(do)'ing
>>> to another account on the desktop if I do setenv DISPLAY :0.0):
>>> 
>>> Caused by: java.awt.AWTError: Can't connect to X11 window server using
>>> '192.168.11.20:0.0' as the value of the DISPLAY variable.
>>> at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
>>> at sun.awt.X11GraphicsEnvironment.access$200(X11GraphicsEnvironment.java:65)
>>> at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:115)
>>> at java.security.AccessController.doPrivileged(Native Method)
>>> at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:74)
>>> at java.lang.Class.forName0(Native Method)
>>> at java.lang.Class.forName(Class.java:264)
>>> at java.awt.GraphicsEnvironment.createGE(GraphicsEnvironment.java:103)
>>> at
>>> java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:82)
>>> at test.scap.TestVideoFrame.testCaptureFrame(TestVideoFrame.java:76)
>>> 
>>> _______________________________________________
>>> > freebsd-java at freebsd.org mailing list
>>> > https://lists.freebsd.org/mailman/listinfo/freebsd-java
>>> > To unsubscribe, send any mail to "freebsd-java-unsubscribe at freebsd.org"
>>> >
>>> 
>>> 
>>> -- 
>>> Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org
>>> _______________________________________________
>>> freebsd-java at freebsd.org mailing list
>>> https://lists.freebsd.org/mailman/listinfo/freebsd-java
>>> To unsubscribe, send any mail to "freebsd-java-unsubscribe at freebsd.org"
>>> 
>>> 
>>> 
>> 
>> Hi,
>> 
>> Can you start any other X application on the VM using the DISPLAY setting? Like /usr/ports/x11/xeyes. Than you know if it is something with X instead of something with Java. I guess it is something with X.
>> I guess your desktop is not listening for external connections to the X server or your routing between the VM and the desktop does not work.
>> Or start a X server in the VM and use DISPLAY=:0.0 again.
> 
>  
> Don't have any X components installed except for the ones required by "make/make install" on openjdk8.   The reason for this post in the first place was to figure out the minimum set of ports needed to get a working DISPLAY variable in the first place. 
> 
> 
> --
> Aryeh M. Friedman, Lead Developer, http://www.PetiteCloud.org

I'm 99% sure you don't need any additional ports to get a working DISPLAY variable.

It will probably help to start your X server with "-listen tcp". But I don't have enough information to be sure about that and how to configure that in your setup.

Ronald.