How to set up a spring-boot application with java 13
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
Update [16 October, 2019]: Spring Boot
2.2.0 has been released.