[SOLVED][SetUp Eclipse on Ubuntu] Observed problems with Java Version

I did setup the IDE for OpenHAB on Elipse on my newly configured Ubuntu machine.
Since this install was as of Nov’19 it came with Java 11 and I followed the advice to install Java 8. I did set the openjdk version “1.8.0_222” as the active version on the system.
When trying to start openHAB I did run into several erros (long list of missing dependencies).
After searching through the messages I stumbled on the NOT changed settings for the correct Java version under: “Windows- Preferences-Java-Installed JRE’s” (just selected the “Java 8 openJDK…” and saved) and under "Windows- Preferences-Java-Installed JRE’s-Execution Environment- JavaSE 1.8. ((just selected the “java 8 openJDK…” and saved).

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I had the same problem. I had to install java 8 manually since it is not in apt repo anymore. After that, you need to remove java 11 package from Eclipse IDE and only leave this Java 8. Only then you would run demo.app

Update: Right click “JRE System Library” from org.openhab.demo.app. From there click on “Installed JRE”, and then remove all JRE except 1.8. Then, i believe you are good to go. Good luck

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It works for me on Java 11 after adding a couple of bundles:

Yes it will still show some informational “illegal reflective access” warnings when running on Java 11. :slight_smile:

Hi @opus and @lsafelix75!

Just a simple question: what version of Java 8 have you installed? openJDK? IBM java? Oracle JDK?

Thanks for your help and best regards,


I installed Oracle Java 8

Thanks Felix!