Calling SOAPPart.setContent() with a DOMSource containing an Element which is a SOAPElement the contents of the body are added twice.

First create a new message from an input stream of a valid message: -

SOAPMessage newMessage = msgFact.createMessage(null, bais);

Then create a new empty message: -

SOAPMessage secondNewMessage = msgFact.createMessage();

Transfer the content from the first message to the second message: -

secondNewMessage.getSOAPPart().setContent(newMessage.getSOAPPart().getContent());

Writing the second message results in the following: -

secondNewMessage.writeTo(baos);

<soapenv:Envelope xmlns:soapenv='http://schemas.xmlsoap.org/soap/envelope/' xmlns:typ='http://www.jboss.org/support/phonebook/types'><soapenv:Header></soapenv:Header><soapenv:Body><typ:lookup xmlns:typ='http://www.jboss.org/support/phonebook/types'>
<!-- This is the first name -->
<firstName>Darran</firstName>
<surname>Lofthouse</surname>
</typ:lookup><typ:lookup xmlns:typ='http://www.jboss.org/support/phonebook/types'>
<!-- This is the first name -->
<firstName>Darran</firstName>
<surname>Lofthouse</surname>
</typ:lookup></soapenv:Body></soapenv:Envelope>