I am creating a spring-boot application, which is running and performing well with openJdk12. The application: https://github.com/jactor-rises/jactor-persistence
I a
You should migrate to using spring-boot 2.2.0 which includes the migration to using Spring Framework 5.2.0
which extends supports until Java-14.
Reference - Spring-Framework-Versions#jdk-version-range
Here are the Draft Release Notes for further information and references and the current version to test this out would be 2.2.0-RC1.
Update [16 October, 2019]: Spring Boot 2.2.0 has been released.