Thanks for the all the exploration and explanation. I offer this summary, for comment:
1. The template starts the route with a Message Exchange Pattern (MEP) "InOnly" or "InOut", depending on whether we use template.sendBody() or template.requestBody() respectively 2. The inOut() and inOnly() set the Message Exchange Pattern (MEP) for whatever they're wrapping. If a to() were used instead, the MEP of the "sub-route" would be the same as the MEP for the "parent" route. So, using inOnly() or inOut() makes sense in a context where one wishes to be explicit for the "sub-route". 3. The MEP used for the "sub-route" determines whether the "parent" route will wait for the "sub-route" and use the out-message of that sub-route as the in-message to its next step. 4. By implication, the MEP of the "sub-route" will not have an effect if the "sub-route" is always synchronous (or always asynchronous). If the "sub-route" is always synchronous, it basically does not support being called with inOnly(). If the sub-route is always asynchronous, it does not support being called with inOut(). Setting the MEP has no impact on such routes. 5. Going back to the original question: since "direct:xyz" is always synchronous, it always works as if it is being called with InOut, regardless of the MEP on the route. I'd appreciate being told if I've got some of that wrong. -- View this message in context: http://camel.465427.n5.nabble.com/Can-t-understand-what-inOnly-is-doing-tp5787961p5788072.html Sent from the Camel - Users mailing list archive at Nabble.com.
