Upgrading from Spring Boot 2.x to Spring Boot 3.0
Most of the time invested in an application’s lifetime is related to maintenance. A successful application may last for years or decades. During this time, it may require upgrades for its evolution. You probably have an application that you want to evolve by taking advantage of the Spring Boot 3 features. In this chapter, we’ll use a sample application that I created using Spring Boot 2.6 and perform gradual upgrades in each recipe. The recipes in this chapter should be done in order, as we’ll use the outcome of one recipe as the starting point for the next. A couple of recipes won’t produce a working version, as there can be compilation errors to be fixed in the following recipes. The last recipe, Using OpenRewrite for migration automation, can be done without completing any previous recipes. However, it requires some of the manual actions explained in the previous recipes.
In this chapter, we’...