Switch to Java 11

[dr0i]

We decided to bring up our java code to a higher, maintained version. Raising java 8 to Java 11 seems to be a good start.

As we want to have our libraries (see metafacture/metafacture-core#518) also to version 11 it's mandatory for compiling to also have the play apps working with java 11.

Compatibility matrix for java, scala and sbt.

To use java 11: change the path of java in your execution environment to java 11. Also set the environment variable JAVA_HOME to java 11.

[dr0i]

We need at least scala 2.12.4 . lobid-gnd already uses this version. @fsteeg can you bring lobid-resources/web to the scala version at leats 2.12.4 and sbt > 1.1.0 as this is the minimum to be able to bump to java 11 ?

[fsteeg]

Updating to Scala 2.12.x would be a major effort, since that would require switching from Play 2.4 (via 2.5) to 2.6. The matrix from above however shows that Java 11 actually supports Scala 2.11.12, and indeed that seems to work: #1967

[dr0i]

You can start the app like sbt start 7200 ? I always encounter:

The java installation you have is not up to date
requires at least version 1.6+, you have
version 11.0.21

which is a Bug an fixed with sbt 1.1.0 at least. Or have I missed something (java -version and JAVA_HOME both point to java 11).

[fsteeg]

You can start the app like sbt start 7200 ?

Oh, no, same issue here. Since sbt run worked, I took a look at the warnings on sbt start. These point to sbt stage, which creates an executable script at ./target/universal/stage/bin/lobid-resources-web.

This script supports a -no-version-check option, which seems to work:

./target/universal/stage/bin/lobid-resources-web -Dhttp.port=7200 -no-version-check

[dr0i]

Ah thx, this is great news ! Have to change start scripts, too, but will work :)

[dr0i]

Will install java 11 tomorrow on both server and configure the start script to use java 11.

[dr0i]

Installed openjdk-11 and set JAVA_HOME to it.
Closed.