How to generate a code to SpringBoot 2.0

Use the content os two links below to convert the projet generated in Spring 1.5.9.RELEASE to 2.1.5.RELEASE:

• https://altkomsoftware.pl/en/blog/spring-boot-migration-java/
• https://stackoverflow.com/questions/56154266/why-does-change-from-spring-boot-version-2-1-4-to-2-1-5-gives-unknown-configurat