Problem with X11 and Headless Exception

Question

Hi,

I'm connecting through ssh with foswiki serwer, where I want to put Your PlantUML plugin, but now I'm trying just to run .jar file with:

java -jar plantuml.jar

and I have a Headless Exception error, when I tried to use as You advised:

/usr/bin/java -Djava.awt.headless=true -jar plantuml.jar

I now have:

Exception in thread "main" java.awt.HeadlessException
    at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:159)
    at java.awt.Window.<init>(Window.java:432)
    at java.awt.Frame.<init>(Frame.java:403)
    at javax.swing.JFrame.<init>(JFrame.java:202)
    at net.sourceforge.plantuml.swing.MainWindow2.<init>(Unknown Source)
    at net.sourceforge.plantuml.Run.main(Unknown Source)

What should I do in this situation? Please help :)

Answer 1

If you are connected only through SSH, you will not be able to run PlantUML in GUI mode.

You should try only in batch mode:

/usr/bin/java -Djava.awt.headless=true -jar plantuml.jar myfile.txt

Comments

Thank you for this answer, but I fixed the problem :)
when I was connecting through SSH, I needed to switch on the X11 server by typing -X flag. Then with headless=true it returned image.png with diagram I wanted :) but I don't know why, GUI was displayed when I ran it :) even with headless=true