Exception when receiving message: setProperty must be overridden by all subclasses of SOAPMessage
While my application worked correctly in Jetty, SOAPified messages were being reject by the same webapp in JBoss. It looked like JBoss was using the wrong class somehow.
From this mailing list entry, I found that I needed to added the following four files. Each has as content a single line:
Deploying the WAR with these changes got rid of the exception.
As a side note, I got the files into my WAR by adding them to src/main/webapp in my project and Maven took care of the rest.