Annotation Type Async
@Target({TYPE,METHOD}) @Retention(RUNTIME) @Documented public @interface Async
Annotation that marks a method as a candidate for asynchronous execution. Can also be used at the type level, in which case all of the type's methods are considered as asynchronous. Note, however, that@Async
is not supported on methods declared within a@Configuration
class.In terms of target method signatures, any parameter types are supported. However, the return type is constrained to either
void
orFuture
. In the latter case, you may declare the more specificListenableFuture
orCompletableFuture
types which allow for richer interaction with the asynchronous task and for immediate composition with further processing steps.A
Future
handle returned from the proxy will be an actual asynchronousFuture
that can be used to track the result of the asynchronous method execution. However, since the target method needs to implement the same signature, it will have to return a temporaryFuture
handle that just passes a value through: e.g. Spring'sAsyncResult
, EJB 3.1'sAsyncResult
, orCompletableFuture.completedFuture(Object)
.- Since:
- 3.0
- Author:
- Juergen Hoeller, Chris Beams
- See Also:
AnnotationAsyncExecutionInterceptor
,AsyncAnnotationAdvisor
Element Detail
value
String value
A qualifier value for the specified asynchronous operation(s).May be used to determine the target executor to be used when executing the asynchronous operation(s), matching the qualifier value (or the bean name) of a specific
Executor
orTaskExecutor
bean definition.When specified on a class-level
@Async
annotation, indicates that the given executor should be used for all methods within the class. Method-level use ofAsync#value
always overrides any value set at the class level.- Since:
- 3.1.2
- Default:
- ""