If you look to the following class of the JPA component which is a idempotentConsumer + Repository you can fetch data from a table to see if they have already been processed, add to the repository the new one and is Tx aware
http://svn.apache.org/repos/asf/camel/trunk/components/camel-jpa/src/main/java/org/apache/camel/processor/idempotent/jpa/JpaMessageIdRepository.java http://camel.apache.org/jpa.html On Thu, Aug 30, 2012 at 3:03 PM, lorenzo <laurent.deco...@sungard.com>wrote: > Hi Charles, > > I did not know about this idempotentConsumer, thanks for that. > > I wonder if it pays off in my case though, as I have to query the > repository > table so I can select things to send out based on what has already been > sent. > > I have done that for now, which I think suffice for my needs: > > @Override > protected int poll() throws Exception { > final int numberOfMessagesPolled = 1; > final Exchange exchange = endpoint.createExchange(); > final MapObject mapObject = > mapRepository.pollNextObject(exchange > .getIn()); > try { > getProcessor().process(exchange); > mapRepository.logMessageProcessed(mapObject); > return numberOfMessagesPolled; > } finally { > if (exchange.getException() != null) { > getExceptionHandler().handleException( > "Error processing > exchange", exchange, > exchange.getException()); > } > } > } > > if getProcessor().process(exchange); fails, then I won't log the message as > being sent. On the other hand if the message is processed, then it is safe > to store the value. > > Chances that the exchange fails after that are small, but existing, so > probably I have to upgrade my solution to the idempotentConsumer, solely > for > having this transactional behaviour... > > > > > -- > View this message in context: > http://camel.465427.n5.nabble.com/Transaction-design-for-a-custom-compononent-tp5718361p5718392.html > Sent from the Camel Development mailing list archive at Nabble.com. > -- Charles Moulliard Apache Committer / Sr. Pr. Consultant at FuseSource.com Twitter : @cmoulliard Blog : http://cmoulliard.blogspot.com
