Java internet connection

[Claude]

One of our products is releases as an "installer" (shell-script made with install4j, not a package). When I install my software on Debian 8 (Jessie) as root (in /opt) the application can access the internet. But when I install it as a regular user (non-root, in ~) it won't be able to connect to the internet.

Can someone explain to me how this works? How does the JRE decide if internet access is allowed or not? How can I check if that is the problem, when internet access fails?
I'm not using a proxy or anything. Internet should just work for all users and applications.
One problem I have is that root (using su) doesn't have access to the desktop, so it can't show my application. But autoupdate is only available in the GUI. And starting it as non-root will fail even with internet because the user doesn't have write access to /opt. We usually have "deb" packages instead of installers, but in this case we still use an installer. Java applications installed as a package don't have that problem (they are also installed as root in /opt).

I'm asking this here because Java is something that runs on a desktop if using Swing as we do.

Note that I did install "default-jre" manually. So I'm just using the default jre based on openjdk 1.8.

Claude

[bw123]

When I install my software on Debian 8 (Jessie) as root (in /opt) the application can access the internet. But when I install it as a regular user (non-root, in ~) it won't be able to connect to the internet.

Have you experienced this problem only on Debian or have you tried other gnu/linux distributions?

[SvetlinZarev]

Does the application throws some exception or writes an error log ? Please post it if it does. Also does the non-root user under which you try to run the app has access to internet ?