Deferred Result

Basic idea

A Spring MVC return type that lets a controller return a placeholder now and resolve it from another thread later, freeing the servlet container thread during the wait. Useful for long-running or asynchronous work without holding a request thread.

Key facts

• DeferredResult<T> releases the request thread until setResult / setErrorResult is called.
• Configurable timeout; lifecycle callbacks (onCompletion, onTimeout, onError).
• Alternatives: Callable<T>, CompletableFuture<T>, reactive Mono/Flux (WebFlux).

Siblings

• Spring