What’s New in Spring Framework 5.2? Kotlin Integration and Reactive Features Explained

Spring Framework 5.2 has been officially released and is available from repo.spring.io or Maven Central.

This version features deep integration with Kotlin 1.3, first‑class support for Kotlin coroutines on top of Spring WebFlux, reactive messaging for the RSocket protocol, and reactive transaction management for R2DBC, MongoDB and Neo4j provided by Spring Data modules.

New Features

Add support for MockRestServiceServer to verify missing headers (#23721)

Set name for shutdown hook threads (#23670)

Use Reactor’s new Schedulers.boundedElastic() (#23661)

Avoid ArrayIndexOutOfBoundsException in SpEL indexer (#23658)

Fix RSocketRequester API to handle requests without payload (#23649)

Allow registration of RSocket metadata extractors (#23645)

Enable constructor injection for @Import and @ComponentScan classes (#23637)

Add SVG mapping to mime.types for JavaMail support (#23629)

Provide support to disable cron‑based scheduled jobs registered via SchedulingConfigurer (#23568)

Log HTTP method in logging filter and adjust log message format (#23567)

Ignore cancellation of transactional Monos in TransactionOperator (#23562)

PathMatchingResourcePatternResolver cannot load resources with ‘#’ in JAR filenames (#23532)

Improve parity between Java and Kotlin router DSLs (#23524)

Offer a memory‑efficient alternative for ClientHttpRequestInterceptor (#22002)

For the full list of changes see the release notes: https://github.com/spring-projects/spring-framework/releases/tag/v5.2.0.RELEASE