Migration to Java 21

[pascalgrimaud]

Different points:

• migrate JHLite engine to Java 21
• migrate generated apps to Java 21

Need to check:

• eclipse-temurin Docker image
• the CI
• etc

[murdos]

Temurin 21 release is delayed because of some legal changes around TCK test licensing: https://adoptium.net/fr/blog/2023/09/temurin21-delay/ Meanwhile we can switch to zulu that has already released its 21 version.

[pascalgrimaud]

About JHLite Engine:

• should we migrate to Java 21 ? I'd vote yes

About generated application:

• should we migrate to Java 21 ? (I'd vote yes)
• if yes, should we keep compatibility with Java 17 ? (I'd vote no)

Maybe it's time to release official 1.0.0 if we decide to push Java 21 as main version

What do you think @murdos @DamnClin @qmonmert ?

[qmonmert]

@pascalgrimaud same

About JHLite Engine:

• should we migrate to Java 21 ? ✅

About generated application:

• should we migrate to Java 21 ? ✅
• if yes, should we keep compatibility with Java 17 ? ❌

[murdos]

About JHLite Engine:

• should we migrate to Java 21 ?

I vote yes too.

About generated application:

• should we migrate to Java 21 ?
• if yes, should we keep compatibility with Java 17 ?

I vote for switching to java 21 by default, but keep compatibility with java 17 a least for a few months. There are companies that might want to use jhipster-lite, that can't yet use java 21 because it's not yet widely available.

[murdos]

I'm going to switch generated applications to Java 21 in a incoming PR, unless someone disagree :-)

[pascalgrimaud]

I'm in favor of migrating to Java 21 for generated app, as it's the new LTS

[murdos]

Bounty claimed: https://opencollective.com/generator-jhipster/expenses/179494

[pascalgrimaud]

@murdos : approved