Document supported return types for @Async methods [SPR-14881]

[spring-projects-issues]

Oliver Drotbohm opened SPR-14881 and commented

It looks like the reference documentation currently doesn't contain any details about the variety of supported return types (Future, ListenableFuture, CompletableFuture).

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Affects: 4.2.8, 4.3.3

Issue Links:

• Support CompletableFuture<> as return type of @Async methods [SPR-13128] #17719 Support CompletableFuture<> as return type of @Async methods
• EnableAsync javadoc not clear enough [SPR-14793] #19359 EnableAsync javadoc not clear enough

Referenced from: commits c8bb32b, 8df45dd, 9be1710

Backported to: 4.2.9