AsyncHandlerMethodReturnValueHandler (Spring Framework 4.3.30.RELEASE API)

All Superinterfaces:
HandlerMethodReturnValueHandler
All Known Implementing Classes:
AsyncTaskMethodReturnValueHandler, CallableMethodReturnValueHandler, CompletionStageReturnValueHandler, DeferredResultMethodReturnValueHandler, HandlerMethodReturnValueHandlerComposite, ListenableFutureReturnValueHandler, ResponseBodyEmitterReturnValueHandler
```
public interface AsyncHandlerMethodReturnValueHandler
extends HandlerMethodReturnValueHandler
```
A return value handler that supports async types. Such return value types need to be handled with priority so the async value can be "unwrapped".
Note: implementing this contract is not required but it should be implemented when the handler needs to be prioritized ahead of others. For example custom (async) handlers, by default ordered after built-in handlers, should take precedence over @ResponseBody or @ModelAttribute handling, which should occur once the async value is ready. By contrast, built-in (async) handlers are already ordered ahead of sync handlers.
Since:
4.2
Author:
Rossen Stoyanchev

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`isAsyncReturnValue(Object returnValue, MethodParameter returnType)`	Whether the given return value represents asynchronous computation.

Methods inherited from interface org.springframework.web.method.support.HandlerMethodReturnValueHandler
handleReturnValue, supportsReturnType

- Method Detail
  - isAsyncReturnValue
```
boolean isAsyncReturnValue(Object returnValue,
                           MethodParameter returnType)
```
    Whether the given return value represents asynchronous computation.
    Parameters:
    returnValue - the value returned from the handler method
    returnType - the return type
    Returns:
    true if the return value type represents an async value