scala3-library_3-3.3.4.jar is using jdk.unsupported apis and not compatible with Java 17/21

[ilapavuluri]

Hi Team,

I am using scala3-library_3-3.3.4.jar in my application, when I run "jdeps --multi-release 21 -jdkinternals" scan I am getting below report:

scala3-library_3-3.3.4.jar -> jdk.unsupported
scala.runtime.LazyVals$ -> sun.misc.Unsafe JDK internal API (jdk.unsupported)

Warning: JDK internal APIs are unsupported and private to JDK implementation that are
subject to be removed or changed incompatibly and could break your application.
Please modify your code to eliminate dependence on any JDK internal APIs.
For the most recent update on JDK internal API replacements, please check:
https://wiki.openjdk.org/display/JDK8/Java+Dependency+Analysis+Tool

JDK Internal API Suggested Replacement

---

sun.misc.Unsafe See https://openjdk.org/jeps/260

Based on this report it looks like scala3-library_3-3.3.4.jar is not compatible with Java 17/21, correct me if I miss anything.

Appreciate any help on this.

[Gedochao]

That doesn't seem right.
sun.misc.Unsafe JDK internal API did get deprecated for removal, yes, but only since JDK 23, in JEP-471 https://openjdk.org/jeps/471

We will be migrating from using the API in Scala 3.8, while we also bump the JDK to 17.
This is tracked under:

• Runtime code implementing lazy val should not use sun.misc.Unsafe on Java 9+ (JEP-471) #9013

Also note that this will not be changed in Scala 3.3 LTS, so if you're interested in newest JDK compat, you should look toward Scala 3.9 LTS down the line.

If you've got further questions on this, feel free to comment under #9013.
Closing this as duplicate/invalid.

[ilapavuluri]

Thank you @Gedochao, as a workaround for now, do I need to add "--add-opens or --add-exports" until I migrate to Scala 3.8 inorder to run my application in Java 21?

[Gedochao]

Thank you @Gedochao, as a workaround for now, do I need to add "--add-opens or --add-exports" until I migrate to Scala 3.8 inorder to run my application in Java 21?

Your application should work on Java 21 without issue.
The deprecation comes online in Java 23, whereas runtime warnings arrive as late as Java 25.
The APIs won't actually get removed until at least Java 26, as per the JEP.

[ilapavuluri]

ok thank you