See forum thread.
I use a file service and forward it to a jms-queue with camel:
from("switchyard://IncomingFile")
// .convertBodyTo(String.class)
.to("switchyard://IncomingQueue");

The message can't be read with HornetQ mixing unless I convert the body to a String. Apparently because the message body is a File-object.
From the documentation I assumed, that when I use WSDL-interfaces, the messages are XML-text-messages which end as TextMessage in the queue.
Similar questions arise with streams. When is a file read as stream, when is it converted to a String? In general: Which classes are used as message body, which are converted implicitly, when do I have to convert explicitly?

It would be helpful to document the behaviour.