Effortlessly Upgrade Your Spring Boot Application: Automate Migration from 2.x to 3.x with OpenRewrite

3 min readJul 28, 2024

In this post, we’ll walk through the process step-by-step, so you can smoothly transition your Spring Boot projects to the latest version. Grab a cup of coffee, and let’s get started! ☕

Why Migrate to Spring Boot 3.x?

Before we dive into the technical details, let’s quickly cover why you might want to migrate to Spring Boot 3.x:

Enhanced Performance: Spring Boot 3.x brings performance improvements and new features that can make your applications more efficient and faster.
Security Updates: Staying up-to-date ensures you’re getting the latest security patches and improvements.
New Features: Explore new capabilities and integrations that can make your development process smoother and more enjoyable.

Sounds good, right? Let’s get into coding!

Step 1: Setting Up OpenRewrite

First things first, you’ll need to set up OpenRewrite in your project. OpenRewrite is a powerful tool that helps automate code changes across your codebase. To get started, add the following dependency to your pom.xml file:

<dependency>
    <groupId>org.openrewrite</groupId>
    <artifactId>rewrite-maven-plugin</artifactId>
    <version>7.x.x</version>
</dependency>

Make sure to replace 7.x.x with the latest version of the plugin.

Step 2: Configuring the Migration Recipe

OpenRewrite uses recipes to define the transformations you want to apply. For the Spring Boot 2.x to 3.x migration, you’ll need to set up a recipe specifically for this upgrade.

Create a file named rewrite.yml in your project's root directory and add the following configuration:

recipes:
  - org.openrewrite.java.spring.boot2to3

This configuration tells OpenRewrite to use the boot2to3 recipe, which is designed to handle common changes between Spring Boot 2.x and 3.x.

Step 3: Running the Migration

With everything set up, it’s time to run the migration! You can do this by executing the following Maven command:

mvn rewrite:run

This command will scan your codebase and apply the necessary transformations to update your project to Spring Boot 3.x. OpenRewrite will automatically refactor your code, making the transition smoother and less error-prone.

Step 4: Review and Test Your Changes

After running the migration, it’s essential to review the changes OpenRewrite made. Check your code for any modifications and ensure everything looks good. Pay special attention to any breaking changes or deprecated features that may require manual intervention.

Once you’ve reviewed the changes, run your tests to ensure everything is working correctly. It’s always a good idea to have a solid test suite in place to catch any issues early.

Step 5: Finalize and Enjoy the Benefits

Congratulations! You’ve successfully migrated your Spring Boot project from 2.x to 3.x using OpenRewrite. This process not only saves you time but also reduces the risk of manual errors. Now, you can take advantage of the latest Spring Boot features and improvements!

As you continue to develop your project, keep an eye out for any additional updates or new features that may enhance your application further. If you have any questions or run into any issues, feel free to drop a comment below. Let’s learn and grow together!

Happy coding! 🚀