where can I find the org.jogamp.java3d source code

I'm trying to track down a null pointer exception
I'm using j3dcore v1.7.
I'm running demo code I found online.
The code just does the following before the NPE:
        GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
        Canvas3D canvas = new Canvas3D(config);

FYI: stack trace

Thread [main] (Suspended (uncaught exception NullPointerException))
        JoglPipeline.getGraphicsConfig(GraphicsConfiguration) line: 8346
        Canvas3D.getGraphicsConfig(GraphicsConfiguration) line: 956
        Canvas3D.<init>(Object, GraphicsConfiguration, boolean) line: 1026
        Canvas3D.<init>(GraphicsConfiguration) line: 988
        SimpleTriangle.<init>() line: 22
        SimpleTriangle.main(String[]) line: 75

Hello

Don't forget --add-opens, etc if you use Java >= 9. Please show your whole source code because "demo code I found online" is vague. Tell us which libraries you put into your classpath, including the third party dependencies. Have you followed the advises of my tutorial?

Thanks for the link to your tutorial. I didn't use --add-opens and I'm using Java >= 9. I will follow your tutorial closely; I'm sure there are several steps there that I need to take. I will discard the tutorial I found and use the ones you've documented instead. Thanks a lot of your help and overall efforts.

You only have to modify the imports to make existing tutorials based on Java3D 1.6 work with Java3D >= 1.7, I only mention the source code, some of them might give very bad advises or obsolete information (information that was true for earlier versions but not now).

I deleted my previous post where I thought jdk 17 didn't support add-opens.
The --add-opens fixed my problem. The demo code is working now.
Thanks again!