Philosophy

This page explains why Arconia Migrations exists, what it focuses on, and how it fits into the wider OpenRewrite ecosystem.

Our Mission

Arconia Migrations provides OSS-licensed (Apache 2.0) OpenRewrite recipes that automate upgrades, refactoring, and code transformations for Java projects. We focus on the Spring ecosystem and ship the upgrade recipes that accompany every release of the Arconia Framework, so that moving to a new version is a single command rather than a manual chore.

Our scope is intentionally focused: we automate the upgrades that Arconia and Spring Boot projects actually run into, rather than aiming to cover every Java framework. Arconia Migrations is a set of standard OpenRewrite recipes. It builds on the OpenRewrite framework rather than replacing it, and you can run it with any OpenRewrite-compatible tool.

Our recipes are not limited to Java source. OpenRewrite parses and transforms Kotlin as well, and changes such as type migrations, method renames, dependency and plugin updates, and configuration property renames apply to Kotlin code just as they do to Java. What is out of scope is Kotlin-specific changes. For example, Spring Boot 4 adopts JSpecify for nullability; if a Kotlin application then resolves null or non-null values incorrectly, such as calling a Spring Boot API that now returns a non-null value, the recipes will not fix that. So you can use Arconia Migrations to upgrade a Spring Boot Kotlin application from 3.5 to 4.1, but any Kotlin-specific follow-up is left to you.

Working with the OpenRewrite Ecosystem

Arconia Migrations builds on the Apache 2.0 recipes in the OpenRewrite catalog and contributes back to them. When an equivalent upstream module is available under the Apache 2.0 license, we prefer to add features and bug fixes there rather than maintain a separate copy. The rewrite-jackson recipes are a good example: a new recipe for Jackson 3 belongs upstream.

To cover the Spring and testing upgrades that Arconia projects rely on, we needed recipes for which no Apache 2.0 module was available in the upstream catalog, so we built our own:

  • rewrite-spring-core and rewrite-spring provide Spring upgrade recipes. They are independent modules and share no code with the OpenRewrite rewrite-spring module, which is distributed under the Moderne Source License.

  • rewrite-testing provides testing recipes for JUnit and Testcontainers, an area served upstream by rewrite-testing-frameworks, which is distributed under the Moderne Source License.

If an Apache 2.0 module covering these areas becomes available upstream, we are happy to contribute to it instead.