javax.xml.soap.SOAPException: InputStream does not represent a valid SOAP 1.1 Message - soap

Question

I am consuming a SOAP API. The XML response I receive is surrounded with a 'soap envelope' - so I need to remove or parse past that wrapper before I can process the XML. I've taken the below approach with other endpoints (so the code is sane, at least) but with this particular endpoint, I get errors.
The error I'm encountering is:
SEVERE: SAAJ0304: InputStream does not represent a valid SOAP 1.1
Message
This is the code I am using to remove the Soap Wrapper:
String soapResponse = getSoapResponseFromApi();
ByteArrayInputStream inputStream = new ByteArrayInputStream(soapResponse.getBytes());
SOAPMessage message = MessageFactory.newInstance().createMessage(null, inputStream);
Document doc = message.getSOAPBody().extractContentAsDocument(); // <-- error thrown here
//unmarhsall the XML in 'doc' into an object
//do useful stuff with that object
here is the XML I am receiving back (the contents of soapResponse in the code above)
<?xml version="1.0" encoding="utf-8"?>
<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<soap:Body>
<XMLContentIActuallyWant xmlns="http://my-url.com/webservices/">
<!-- Useful stuff here -->
</XMLContentIActuallyWant >
</soap:Body>
</soap:Envelope>

Answer 1

I discovered the solution as I was preparing this question.
Soap versions have different formatting. The SoapMessage library was defaulting to soap 1.1 - but the contents of the response I was receiving was soap 1.2.
I could see this when I inspected the full request that was being sent, in order to receive the response noted above - it looked like this:
<?xml version="1.0" encoding="utf-8"?>
<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap12="http://www.w3.org/2003/05/soap-envelope">
<soap12:Body>
<!-- xml content here -->
</soap12:Body>
</soap12:Envelope>
the soap12 part highlights that it is requesting soap 1.2.
so although the response doesn't contain the '12' - the response is also in 1.2.
So we need to tell SoapMessage to use 1.2 instead of the default (1.1 in my case).
I did this by modifying my code above like so:
Before:
SOAPMessage message = MessageFactory.newInstance().createMessage(null, inputStream);
After:
SOAPMessage message = MessageFactory.newInstance(SOAPConstants.SOAP_1_2_PROTOCOL).createMessage(null, inputStream);
It's worth noting that other endpoints of the same API served SOAP 1.1 - which is why this error was so confusing for me. I was doing the same thing and getting different results.