I have come across other similar question here. Both of above answers are perfect, but here trying to add additional information for someone looking for SOAP1.1, and not SOAP1.2.
Just change one line code provided by @acdcjunior, use SOAPMessageFactory1_1Impl
implementation, it will change namespace to xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/", which is SOAP1.1 implementation.
Change callSoapWebService
method first line to following.
SOAPMessage soapMessage = SOAPMessageFactory1_1Impl.newInstance().createMessage();
I hope it will be helpful to others.