In this article, you will learn about:

• The motivation behind writing this article
• The architecture of the Spring Petclinic Rest project
• The architecture of the Helidon Petclinic project
• How to migrate the data module
• How to migrate REST controllers
• How to write tests
• Interesting issues and pitfalls, along with their solutions

Motivation

Initially, I anticipated the article would be short, but it ended up being quite lengthy. You could think of it as a missing chapter from the “Beginning Helidon” book I co-authored with my colleagues. Yes, it’s a bit cheesy to advertise the book in the first paragraph. You might assume that promoting the book was my sole motivation for writing this article. Admittedly, it’s a significant motivator, but not the only one.

In the Helidon support channels, we frequently encounter questions about migrating Spring Boot applications to Helidon. To address these inquiries, we concluded that creating a Helidon version of the well-known Spring Petclinic demo application and documenting the migration strategies and challenges would be the best approach. I volunteered for the task because of my previous experience with Spring programming and because I hadn’t engaged in real programming for quite some time, and I wanted to demonstrate that I still could. Whether I succeeded or not, you readers can decide after reviewing the work. Perhaps I shouldn’t have taken it on. You can find the result here. Anyway, enough philosophical musings; let’s get down to business.