Soap - passing xml in the request

I'm trying to pass an xml in the body of a Soap request.

my problem is that i can't get the exact structure i need.

i need the body to be in the structure of: <soap:Body> xmlString </soap:Body>.

I know of 2 ways to set the SOAP request body:

1 . body.addBodyElement(envelope.createName(xmlString));

this create a structure of <soap:Body> < xmlString > </soap:Body> which isn't what i want. (surrounds the string's content with <> )

2 . SOAPBody sb = sm.getSOAPBody();

 sb.addTextNode(xmlString);

this creates the desired structure but completely mess up the xml characters, replacing spaces and <> in things such &lt.

my code is :

SOAPConnectionFactory sfc = SOAPConnectionFactory.newInstance();
          SOAPConnection connection = sfc.createConnection();
          MessageFactory mf = MessageFactory.newInstance(SOAPConstants.SOAP_1_2_PROTOCOL);
          SOAPMessage sm = mf.createMessage();
          sm.getSOAPPart().getEnvelope().setPrefix("soap");
          sm.getSOAPPart().getEnvelope().removeNamespaceDeclaration("env");
          sm.getSOAPHeader().setPrefix("soap");
          sm.getSOAPBody().setPrefix("soap");
          SOAPBody sb = sm.getSOAPBody();
          sb.addTextNode(xml);

          System.out.println("\n Soap Request:\n");
          sm.writeTo(System.out);
          System.out.println();

is there any way to get it to be in the format i need? thanks