Will there be issue deploying AEM Bundles compiled on Java 11 to the AEM Instance running in Java 8?

[BinaryAlchemy11]

Will there be an issue on doing this?

I have a bundle build locally in Java 11. But the in house AEM instance that I am trying to deploy to is running in Java 8. Will this create compatibility issue for the bundles once deployed to the AEM instance running in Java8?

If yes, is there a solution on how we need to proceed?

[BrianKasingli]

Yes, Deploying a bundle (software package) built with Java 11 to an AEM instance running Java 8 can cause problems. Java 11 has new features and changes that Java 8 doesn’t recognize, so this could lead to errors. AEM bundles compiled on Java 11 to an AEM instance running on Java 8 will indeed cause compatibility issues. Java 11 introduced several changes, including new APIs and the removal of certain deprecated components present in Java 8. When a bundle is compiled in Java 11, it often relies on classes and bytecode instructions that are not supported by Java 8, leading to errors such as UnsupportedClassVersionError upon deployment.

Solution on how you need to proceed:

1. Re-Configure Dev Environment & Recompile the Bundle with Java 8: Update your local machine with JDK 8. Update IDE to use Java 8 and fix all problems if you do see them. Rebuild the bundle using Java 8 so it matches what’s on the server. Re-initialize your AEM environment on your local machine with Java 8. Re-test all custom code of your AEM application.

2. (if Possible) Upgrade the Server to Java 11: If possible, upgrade the AEM server to use Java 11 to match your bundle.

[BinaryAlchemy11]

Thanks for the reply.

I did see in some of the resources online that the Java is forward compatible.

Does this mean that there won't be any issue if the AEM server is running in Java 11 and we deploy the bundle (software package) build with Java 8 locally to the AEM server?

[BinaryAlchemy11]

Any update on the follow up question please?

[kautuk_sahni]

@BinaryAlchemy11 Did you find the suggestion helpful? Please let us know if you require more information. Otherwise, please mark the answer as correct for posterity. If you've discovered a solution yourself, we would appreciate it if you could share it with the community. Thank you!

[BinaryAlchemy11]

Solution is helpful but waiting on the followup question to mark it as correct one.