SOAPMessage message = MessageFactory.newInstance().createMessage();
SOAPPart sp = message.getSOAPPart();
SOAPEnvelope envelope = sp.getEnvelope();
SOAPBody bdy = envelope.getBody();
SOAPElement sbe = bdy.addChildElement(new SOAPBodyElementRpc(envelope.createName("echoString", "ns1", TARGET_NAMESPACE)));
sbe.addChildElement(envelope.createName("String_1")).addTextNode("Hello");
sbe.addChildElement(envelope.createName("String_2")).addTextNode("world!");
return message;
}