What is the best way to reject messages with the same body in AMQ queue?

Question

I have a single AMQ queue that receives simple messages with string body. Consider I'm sending CLSIDs as message bodies. CLSIDs could be not unique, but I'd like to reject all messages with not unique bodies and keep only single instance of such messages in the queue. Is there any simple way to do it?

Currently I'm using a workaround. Messages from the queue are consumed by some processor that tries to insert bodies into a simple DB table with UNIQUE constraint applied to message_body field. If processor inserts the messages succesfuly - it's assigned to exchange.out.body and sent to other queue. If ConstraintViolationException is thrown - nothing is resent to other queue.

I would like to know does AMQ support something similar out of the box?

Answer 1

I believe you can write an interceptor for activemq where you can perform certain actions on messages. Check out: http://activemq.apache.org/interceptors.html

That being said, in my personal opinion this is bad practice. ActiveMQ is a messaging system which should only be responssible for transport of the message. All logic can beter be performed using your application ( either make sure the sender cannot send the same message more then once OR , create an intermediate consumer which indeed matches the received body with a database that contains already seen message bodies BEFORE, routing the message to the actual receiver queue)