file inbound-channel-adapter not creating messages - file

Question

We are working on a POC to use Spring integration and Rabbit MQ. We have two modules producer module and consumer module both are runs in different JVMs. The Producer module listen on a Folder (input folder) as soon as new files arrives, creates a message then push to (incoming.q.in) queue and also move to process folder.
In the producer module we have below code. When I dropped about 100 files in incoming folder about 90 files processed and moved to process folder but 10 files didn't move to process folder.
For failed cases these are the messages in log file
....
[07/30/13 07:34:23:023 EDT] [taskExecutor-3] DEBUG org.springframework.integration.file.FileReadingMessageSource Added to queue: [test.xml]
[07/30/13 07:34:23:023 EDT] [taskExecutor-3] DEBUG org.springframework.integration.endpoint.SourcePollingChannelAdapter Received no Message during the poll, returning 'false'
....
for Successful case
....
[07/30/13 07:34:32:032 EDT] [taskExecutor-1] DEBUG org.springframework.integration.file.FileReadingMessageSource Added to queue: [test_0.xml]
[07/30/13 07:34:32:032 EDT] [taskExecutor-1] INFO org.springframework.integration.file.FileReadingMessageSource Created message: [[Payload=/apps/incoming/test_0.xml][Headers={timestamp=1375184072466, id=d8d4cea4-a25d-4869-b287-e76cfb76f554}]]
....
Here is the code
<file:inbound-channel-adapter id="inboundAdapter" channel="inboundChannel" directory="file:${incoming_folder}" prevent-duplicates="true" filename-pattern="*.*" auto-startup="true" >
<int:poller id="fileInboudPoller" fixed-rate="3" receive-timeout="3" time-unit="SECONDS" max-messages-per-poll="1" task-executor="taskExecutor"/>
<file:nio-locker />
</file:inbound-channel-adapter>

Answer 1

It generally means the locker couldn't lock the file (presumably because the file is in use elsewhere).
BTW, a common error with applications like these is copying files "in place" such that the consumer might see an incomplete file.
A common technique to avoid these issues is to copy the file with a temporary name and rename it only when it is completely written.