Invoked inside the {@link Runnable} submitted to the Executor after calling
the target MessageHandler regardless of the outcome (i.e. Exception raised
or not) thus allowing for proper resource cleanup.
<p>Note that this will be invoked only if beforeHandle successfully completed
and returned a Message, i.e. it did not return {@code null}.
@param message the message handled
@param channel the channel on which the message was sent to
@param handler the target handler that handled the message
@param ex any exception that may been raised by the handler
Invoked inside the {@link Runnable} submitted to the Executor after calling the target MessageHandler regardless of the outcome (i.e. Exception raised or not) thus allowing for proper resource cleanup. <p>Note that this will be invoked only if beforeHandle successfully completed and returned a Message, i.e. it did not return {@code null}. @param message the message handled @param channel the channel on which the message was sent to @param handler the target handler that handled the message @param ex any exception that may been raised by the handler