The Poll Message activity is a starter activity that polls
the configured queue for the message. This activity supports the ATLEAST
ONCE and EXACTLY ONCE delivery semantics. The Poll Message Activity
supports batching, if the batching option is selected.
The EXACTLY ONCE delivery semantic is handled through the
message acknowledgement. Since the JMS provider must never deliver
a copy of an acknowledged message, the Poll Message activity leverages
the provider for the EXACTLY_ONCE delivery semantic. When the batching
option is selected, if there is more than one message in the queue,
the activity processes all the messages at once, instead of processing
them one at a time.
Important: This orchestration must
have a JMS endpoint representing the data source, otherwise, output
mapping is disabled.