Github user afs commented on the issue:
https://github.com/apache/jena/pull/474
"should be used with JDK 1.8" has several facets.
There are different levels of Java11 usage: the project discussions back
when it was Java9:
[dev@
message](https://lists.apache.org/thread.html/880632ba6b6df6f2b26e4357462d94426ea4b14d83f08e9edac0b684@%3Cdev.jena.apache.org%3E)
and sent as part of [users@
message](https://lists.apache.org/thread.html/5b31a3b6794781f6a02658608444043b5535957a6c94f3728efd8304@%3Cusers.jena.apache.org%3E).
Ultimately, it is a community decision.
My personal opinion is that Jena should be able to run on Java8 runtime.
Research projects may upgrade quickly but enterprise deployments are another
matter.
To ensure no accidents, I prefer the release build used Java8 because it
protects against runtime library changes (we have one currently about
tools.jar).
I'd like the build to work with Java11 - hence the commented line in the
parent `pom.xml` and the Jenkins job, both of which came out of the project
discussions from Feb. Currently, "-Pdev" works, the full release build does not.
I have `~/.mavenrc` setup to make sure I gets builds right. I use JDK10 as
the default java on my system (I am resisting installing Java11 manually and
waiting for Ubuntu ... at least for now!), I make sure maven runs with Java8.
# ~/.mavenrc
JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
Java11 will change the ecosystem and we don't know how that plays out or
what may come out of [adoptjava](https://adoptopenjdk.net/) and the Jan2019
deadline from Oracle. I think it will rapidly become clear.
---
