in ServiceMix 3.x.x I used exchange listeners
(by implementing org.apache.servicemix.jbi.event.ExchangeListener and registering it in conf/servicemix.xml etc).
Is there a similiar functionality in esb 4.0 preview ? Couldn't find it in the documentation.
The ExchangeListener functionality hasn't been added to the preview release of ESB 4, but we do plan to have this kind of feature in ESB 4 as well. In addition to that, we are also planning to add a more powerful interceptor feature, which will allow you to change and redirect MessageExchanges that pass through the NMR.