Consistently support CompletionStage next to CompletableFuture [SPR-15258]

[spring-projects-issues]

Juergen Hoeller opened SPR-15258 and commented

As of 4.2, we're supporting CompletableFuture for MVC handler methods and message handler methods, but its sibling CompletionStage only for MVC handler methods. Let's fix this gap for 4.3.7, supporting CompletionStage return types there as well, and document that support for both kinds of handler methods.

---

Affects: 4.3.6

Issue Links:

• Support CompletableFuture as return value in @MessageMapping handlers [SPR-12207] #16821 Support CompletableFuture as return value in @MessageMapping handlers
• Support CompletableFuture as alternative to DeferredResult in MVC [SPR-12597] #17198 Support CompletableFuture as alternative to DeferredResult in MVC
• Async annotation should allow for non-blocking execution with CompletableFuture [SPR-15401] #19964 Async annotation should allow for non-blocking execution with CompletableFuture