openJDK (JDK vs JRE)

So I just figured out what the difference between “main” and “universe” is in the /etc/apt/sources.list by this nice article

mine is set to universe… so I searched for the reason why I need universe on my seafile.
Then I found out that its was done backthen for openJDK…

Then I saw that the are multiple versions of JDK:

  • openjdk-13-jdk (universe, Java Development Kit for developers)
  • openjdk-13-demo (universe, example files for Java)
  • openjdk-13-doc (universe, documentation for developers)
  • openjdk-13-jre-headless (universe, smaller Java runtime environment for monitorless servers)
  • openjdk-13-source (universe, source packages of Java)

even if this is v13 this still relates to v8.

Now I question my self if I could have gotten away with the jre-headless version for my seafile server.
I’m not sure if the developers just recommended the JDK version because they need it on their dev-Systems or if we (customers/users) all need the JDK version too, for “just” running the seafile server…

Is there anyone out here running seafile on: openjdk-8-jre-headless ?

I think I am.

apt list --installed|grep jdk

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

openjdk-8-jre/bionic-updates,bionic-security,now 8u252-b09-1~18.04 amd64  [installiert]
openjdk-8-jre-headless/bionic-updates,bionic-security,now 8u252-b09-1~18.04 amd64  [Installiert,automatisch]

Thanks I’ll give it a try when i find some time