Null Safety in Spring applications with JSpecify and NullAway
The initial introduction of the null safety support in Spring dates back to 2017 and the release of Spring Framework 5.0. In 2025, we are evolving that story to bring more added value for Spring developers, either in Java or Kotlin. But before having a deeper look to the changes we are working on, let me explain why we do that and what are the expected benefits.
What problem do we try to solve?
Let's take a concrete example, and say we are using a library that provides a TokenExtractor
interface defined as follow:
interface TokenExtractor {
/**
* Extract a token from a {@link…