AOP Alliance MethodInterceptor that processes method invocations
asynchronously, using a given AsyncTaskExecutor.
Typically used with the Async annotation.
In terms of target method signatures, any parameter types are supported.
However, the return type is constrained to either void or
java.util.concurrent.Future. In the latter case, the Future handle
returned from the proxy will be an actual asynchronous Future 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 temporary Future handle that just passes the return value through
(like Spring's AsyncResult
or EJB 3.1's javax.ejb.AsyncResult).
When the return type is java.util.concurrent.Future, any exception thrown
during the execution can be accessed and managed by the caller. With void
return type however, such exceptions cannot be transmitted back. In that case an
AsyncUncaughtExceptionHandler can be registered to process such exceptions.
As of Spring 3.1.2 the AnnotationAsyncExecutionInterceptor subclass is
preferred for use due to its support for executor qualification in conjunction with
Spring's @Async annotation.
This implementation searches for a unique TaskExecutor
bean in the context, or for an Executor bean named "taskExecutor" otherwise.
If neither of the two is resolvable (e.g. if no BeanFactory was configured at all),
this implementation falls back to a newly created SimpleAsyncTaskExecutor instance
for local use if no default could be found.