MessageListener interface strictly define behavior of listeners in multithreaded environment (http://java.sun.com/j2ee/1.4/docs/api/javax/jms/MessageListener.html). Session should serialize dispatching of messages to listener, so you don't need any additional synchronization primitives over MessageListener. But you should not register one MessageListener in several Sessions at the same time.
Denis Bazhenov On Apr 10, 2010, at 12:30 AM, frbo wrote: > I wonder: should I make use a 'synchronized' version for the collections > that are accessed in the 'onMessage' t
