What’s New in Spring 6? Key Changes for Jakarta EE Migration and Web Development

Core Changes

The @Inject annotation from JSR‑330 is now located in the jakarta.inject package. JSR‑250 annotations @PostConstruct and @PreDestroy have moved to jakarta.annotation. Spring still detects these annotations under the javax package, including common usage in pre‑compiled binaries. ListenableFuture has been deprecated and fully replaced by CompletableFuture (see issue 27780).

Data and Transactions

Due to the Jakarta EE migration, upgrade to Hibernate ORM 5.6.x and use the hibernate-core-jakarta artifact, switching imports from javax.persistence to jakarta.persistence. The corresponding Hibernate Validator version is 7.0.x, based on jakarta.validation.

Web Applications

Upgrade to Tomcat 10, Jetty 11, or Undertow 2.2.14 and use the undertow-servlet-jakarta component, changing imports from javax.servlet to jakarta.servlet. Deprecated servlet components include Commons FileUpload, Tiles, and FreeMarker JSP support; use StandardServletMultipartResolver for file uploads and focus on a REST‑oriented architecture.

Spring MVC and Spring WebFlux no longer treat @RequestMapping alone as a controller. Interface‑based AOP proxies may not apply; enable class‑based proxies or annotate interfaces with @Controller (see issue 22154). HttpMethod is now a class instead of an enum. Code using EnumSet<HttpMethod> should switch to Set<HttpMethod> and use if‑else rather than switch (see issue 27697).

Kotlin extension function WebTestClient.ResponseSpec::expectBody now returns BodySpec instead of KotlinBodySpec. The consumeWith method is no longer available. Spring 6.0 uses Kotlin 1.6, fixing bug KT‑5464.

RestTemplate’s HttpComponentsClientHttpRequestFactory now requires Apache HttpClient 5.