Why

This is intended to be a POC that show how we can leverage a tool like Open-rewrite to update our codebase running on old JDKs to new ones. The target is to start from java11 and see how we can push it to java17

Start

• Create a naive spring boot app running on Java11
• Start with the open re-write tool and apply the default implementation to update it a little
• See how you can add your own rule and how open re-write can use that to update the code base
• Maybe introduce other tools which traverses over an AST and produces something entirely different
  • ErrorProne
  • ErrorChecker
  • Antlr
  • ...

POC Flow and Code Organisation

• v1_0: Plan here is to write a naive code base and see what open re-write does to it.

  • Packages
    • Services - Business logic as interfaces will be here, together with an implementation package
    • Controllers - Classes that exposes REST endpoint in the spring way
    • Models - Data Structures describing the business domains and data access objects
    • Configs - Spring managed classes

• v2_0: Plan here is to write a code base with a data access layer or connection to a DB

  • Packages: v_1 +
    • Entities - Data Structures describing the business domains, and a reflection of the DB
    • Repositories - Jpa Interfaces that allows communication with the DB