[midPoint] MidPoint support for Java platform versions

[Radovan Semancik]

Dear midPoint community,

Up until midPoint 4.0 we have supported only Java 8. MidPoint 4.0 is the 
first version that supports both Java 8 and Java 11. The "Gutenberg" 
family (4.0.x releases) is also the last release chain that will support 
both Java versions. Java 8 support is currently deprecated in midPoint 
4.0 and it will be removed in midPoint 4.1. Therefore all releases 
beyond 4.1 will be Java 11 only.

This means that the "Gutenberg" chain (4.0.x) can still run on Java 8 
and we hope that we will support Java 8 for the entire support lifetime 
of Gutenberg. As this is an LTS chain, Java 8 may in fact be supported 
for quite a long time. However, we may be forced to discontinue Java 
support sooner than we currently plan. This may happen in case that Java 
8 itself will "die" before the 4.0.x support lifetime ends. We would 
like to support Java 8 as long as possible, but there may be external 
factors that could make such support infeasible. For example if Java 8 
security fixes will no longer be publicly available we could not 
reproduce the JVM problems and therefore we could not fix them. Is such 
case we would be forced to revoke Java 8 support even from the 4.0.x LTS 
release chain. Let's hope that this won't happen. However, midPoint 4.0 
"runs like heaven on JDK11", therefore all users of midPoint 4.0+ are 
strongly recommended to upgrade to Java 11.

Java 11 will be the only option for MidPoint 4.1 and later. Those are 
non-LTS feature releases. The basic idea for non-LTS releases is the 
ability to move faster and quickly deliver new improvements and 
features. Java 8 support would hold us back. Therefore we will support 
Java 11 only.

The bottom line is that you should upgrade to Java 11 together with 
upgrade to MidPoint 4.0. That is the recommended approach for all 
midPoint deployments.

-- 
Radovan Semancik
Software Architect
evolveum.com