JAVA Soap response getContent OK but body empty

I'm new with soap :)

I make soap request to the server all is ok. Get the response in SOAPMessage like this :

SOAPMessage soapResponse = soapConnection.call(soap, url);

I print it with this :

TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
Source sourceContent = soapResponse.getSOAPPart().getContent();
System.out.print("\nResponse SOAP Message = ");
StreamResult result = new StreamResult(System.out);
transformer.transform(sourceContent, result);

and I got this :

Response SOAP Message = <?xml version="1.0" encoding="UTF-8"?><SOAP-ENV:Envelope xmlns:SOAP-ENV="http://ift.tt/sVJIaE" xmlns:xsd="http://ift.tt/tphNwY" xmlns:xsi="http://ift.tt/ra1lAU"><SOAP-ENV:Body><xsd:PMT>NOK</xsd:PMT></SOAP-ENV:Body></SOAP-ENV:Envelope>

all is ok. The problem is when I want to get body with this :

soapResponse.getSOAPBody();

this return : [SOAP-ENV:Body: null]

I would like to get the body and manipulate (the xml) easily

Thanks