Wire tap
Channel
The channel to put the intercepted messages on.
Selector expression
A boolean SpEL expression evaluated against the message to determine whether it should sent to the intercepting channel.
Default is empty, which will cause every message to be intercepted and send to the wire tap channel.
Timeout
The timeout when sending to the wire tap channel.
A positive value indicates the maximum amount of time (in milliseconds) for waiting on a successful send when the channel is at capacity. A value of zero indicates no waiting at all if the channel is at capacity at the moment of the initial attempt. A negative value indicates waiting indefinitely for a successful send when the channel is at capacity.
Default is 0, which indicates no waiting for a successful send to the wire tap channel.