Spring Boot Properties Migrator: How to Migrate Your Application Properties with Ease

Learn how to migrate your Spring Boot application properties effortlessly with the Spring Boot Properties Migrator. Find out how to run it, and interpret its output.

Introduction

Spring Boot is a popular framework for building Java applications, providing a streamlined approach to building and deploying applications. However, as with any framework, updates and new releases are frequently released, and developers need to ensure their applications are up-to-date with the latest features, security patches, and bug fixes. One critical aspect of updating your application to the latest version of Spring Boot is migrating your properties files. These files contain important configuration data your application relies on to run correctly.

Fortunately, the Spring Boot team has created a tool to simplify the process of migrating your properties files: the Spring Boot Properties Migrator. In this guide, we’ll walk you through how to use this tool to streamline the property migration process.

Step 1: Add the Spring Boot Properties Migrator Dependency

To use Spring Boot Properties Migrator, you first need to add the dependency to your project. You can do this by adding the following code to your project’s pom.xml file:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-properties-migrator</artifactId>
  <version>{{spring-boot-properties-migrator-version}}</version>
  <scope>runtime</scope>
</dependency>

The runtime scope ensures that the dependency is only included when your application runs and not during compilation.

The latest version of the dependency can be found here.

Step 2: Run Your Application

Once you have added the dependency to your project, you can run your Spring Boot application as usual. The Spring Boot Properties Migrator will automatically detect any deprecated or renamed properties. It will not only analyze your application’s properties and print results at startup. Also, it will temporarily migrate properties at runtime.

Example

Let’s say we want to migrate our application from Spring Boot version 2.7.10 to version 3.0.5 and we have some properties related to metrics that have been renamed/migrated in the case of a newer version of Spring Boot version.

management.metrics.export.signalfx.enabled=false
management.metrics.export.signalfx.step=30s

Now, when we run the application, it will produce the output like below.

2023-04-02T19:21:25.257+05:30  WARN 240 --- [           main] o.s.b.c.p.m.PropertiesMigrationListener  : 
The use of configuration keys that have been renamed was found in the environment:

Property source 'Config resource 'class path resource [application.properties]' via location 'optional:classpath:/'':
	Key: management.metrics.export.signalfx.enabled
		Line: 1
		Replacement: management.signalfx.metrics.export.enabled
	Key: management.metrics.export.signalfx.step
		Line: 2
		Replacement: management.signalfx.metrics.export.step


Each configuration key has been temporarily mapped to its replacement for your convenience. To silence this warning, please update your configuration to use the new keys.


Process finished with exit code 130

This warning message indicates that the Spring Boot Properties Migrator has detected the use of deprecated or renamed properties in our application’s configuration. The message lists each deprecated property and its corresponding replacement property, along with the line number in the configuration file where the property is defined.

The report also includes the property source where each deprecated or renamed property was found. In this case, the property source is the application.properties file located in the project classpath.

FAQs

Things to Consider

When working with Spring Boot Properties Migrator, it is important to consider the following:

• Determine if you actually need to use the migrator: Before adding the migrator dependency to your project, it’s important to first determine if you actually need it. If you’re not upgrading your Spring Boot version or your application doesn’t have any properties that need to be migrated, then you can skip this step.
• Include the migrator as a runtime dependency: To use the migrator, you need to include it as a runtime dependency in your project. Make sure to specify the correct version of the dependency in your project’s pom.xml or build.gradle file.
• Test your application: After updating your properties files, it’s important to thoroughly test your application to ensure that everything is working as expected. Verify that your application’s behavior has not been affected by the changes made during the migration process.

Conclusion

Updating your Spring Boot applications to the latest version is critical to keep your application secure, performant, and feature-rich. However, updating your properties files can be a daunting task. The Spring Boot Properties Migrator provides a streamlined approach to migrating your properties files, making the process faster and more reliable. By using the steps outlined in this guide, you can easily use the migrator with Maven to simplify the property migration process and ensure that your applications are up-to-date with the latest version of Spring Boot.

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