OFBIZ-13306: JAVA 21 migration

[gtchaboussie]

Changed: Migration to Java 21
(OFBIZ-13306)

Migration to Java 21

Thanks: Jacques for the warnings work and Nicolas.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[JacquesLeRoux]

I did not look at it yet, we got this:

Execution failed for task ':compileJava'.

error: invalid source release: 21

[ieugen]

@gtchaboussie : thanks for the contribution.

I think you are also trying to increase the java source level - which might not be in scope right now.

The important part is that OFBiz can be built using JDK-21.
I don't believe it means we need to increase source level to 21 so only JDK-21+ can build OFBiz.
I think the source level/version can stay on 17 and have OFBiz build with JDK17 and JDK21

The build fails right now because the CI server uses only JDK-17.
It would be great to have OFBiz tested with multiple JDK versions at once (JDK build matrix) - but some other time.

Regarding source level increase, looking at https://docs.oracle.com/en/java/javase/21/language/java-language-changes-summary.html , the only language changes that are new from 17->21 are:

Record Patterns (JEP 440)

Pattern Matching for switch Expressions and Statements (JEP 441)

Not sure if those are enough to warrant a source level increase.
Should ask on ML.