All Superinterfaces:
HandlerMethodReturnValueHandler
All Known Implementing Classes:
AbstractAsyncReturnValueHandler, CompletableFutureReturnValueHandler, HandlerMethodReturnValueHandlerComposite, ListenableFutureReturnValueHandler
```
public interface AsyncHandlerMethodReturnValueHandler
extends HandlerMethodReturnValueHandler
```
An extension of HandlerMethodReturnValueHandler for handling async, Future-like return value types that support success and error callbacks. Essentially anything that can be adapted to a ListenableFuture.
Implementations should consider extending the convenient base class AbstractAsyncReturnValueHandler.
Since:
4.2
Author:
Rossen Stoyanchev
See Also:
AbstractAsyncReturnValueHandler

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`isAsyncReturnValue(Object returnValue, MethodParameter returnType)`	Whether the return value represents an asynchronous, Future-like type with success and error callbacks.
`ListenableFuture<?>`	`toListenableFuture(Object returnValue, MethodParameter returnType)`	Adapt the asynchronous return value to a `ListenableFuture`.

Methods inherited from interface org.springframework.messaging.handler.invocation.HandlerMethodReturnValueHandler
handleReturnValue, supportsReturnType

- Method Detail
  - isAsyncReturnValue
```
boolean isAsyncReturnValue(Object returnValue,
                           MethodParameter returnType)
```
    Whether the return value represents an asynchronous, Future-like type with success and error callbacks. If this method returns true, then toListenableFuture(java.lang.Object, org.springframework.core.MethodParameter) is invoked next. If it returns false, then HandlerMethodReturnValueHandler.handleReturnValue(java.lang.Object, org.springframework.core.MethodParameter, org.springframework.messaging.Message<?>) is called.
    Note: this method will only be invoked after HandlerMethodReturnValueHandler.supportsReturnType(org.springframework.core.MethodParameter) is called and it returns true.
    Parameters:
    returnValue - the value returned from the handler method
    returnType - the type of the return value
    Returns:
    true if the return value type represents an async value
  - toListenableFuture
```
ListenableFuture<?> toListenableFuture(Object returnValue,
                                       MethodParameter returnType)
```
    Adapt the asynchronous return value to a ListenableFuture. Implementations should consider returning an instance of SettableListenableFuture. Return value handling will then continue when the ListenableFuture is completed with either success or error.
    Note: this method will only be invoked after HandlerMethodReturnValueHandler.supportsReturnType(org.springframework.core.MethodParameter) is called and it returns true.
    Parameters:
    returnValue - the value returned from the handler method
    returnType - the type of the return value
    Returns:
    the resulting ListenableFuture, or null in which case no further handling will be performed

Interface AsyncHandlerMethodReturnValueHandler

Method Summary

Methods inherited from interface org.springframework.messaging.handler.invocation.HandlerMethodReturnValueHandler

Method Detail

isAsyncReturnValue

toListenableFuture