This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
"Bubbles" check your Private Messages for an important JavaRanch message.
Not sure what your question is, but the responsibility of the JMS Message Handler is to convert the JMS Message to a Spring Integration Message object type. While the two Message types are very similar in that they have a "body" in JMS it is called the "payload" in SI. And in SI we have a Header, where in JMS it is Properties. If you have a scenario where you are passing through SI, so receive a JMS message on one channel and send it out on another channel with JMS adapters you can configure it to just pass the whole JMS message as a payload in a Spring Integration channel which then takes that payload to the outbound channel to JMS. That would have no overhead as it is just a passthrough.
If you have a complicated JMS message with lots of Properties, it might take a few more milliseconds to convert those into SI Message header values.