SOAP headers can be added to a Web service request in different ways, if you use Apache CXF. The way I prefer is the one I’ve mentioned here – as it doesn’t require changes to wsdl or method signatures and it’s much faster as it doesn’t break streaming and the memory overhead is less.

The headers in the list are streamed at the appropriate time to the wire according to the databinding object found in the Header object.

About SOAP headers,

Like any good messaging protocol, SOAP defines the concept of a message header. It is an optional part of any SOAP message. If it exists, the header contains application-specific information (like authentication, payment, etc) about the SOAP message i.e. information about the message, or about the context in which the message is sent, or basically whatever the creator of the message thought was a good idea to put there instead of the actual body of the message. If the Header element is present, it must be the first child element of the Envelope element.

/**
* @author Singaram Subramanian
*
*/

/* Create a ClientProxyFactoryBean reference and assign it an instance of JaxWsProxyFactoryBean, a factory for creating JAX-WS proxies. This class provides access to the internal properties used to set-up proxies. Using it provides more control than the standard JAX-WS APIs. */

ClientProxyFactoryBean factory = new JaxWsProxyFactoryBean();
factory.setServiceClass(singz.ws.cxf.sample.SampleServiceInterface.class);

// Set the web service endpoint URL here
factory.setAddress("http://xxx.xxx.com/services/SampleService/v1");

SampleServiceInterface serviceClient = (SampleServiceInterface) factory.create();

// Get the underlying Client object from the proxy object of service interface
Client proxy = ClientProxy.getClient(serviceClient);

// Creating SOAP headers to the web service request

// Create a list for holding all SOAP headers
List<Header> headersList = new ArrayList<Header>();

Header testSoapHeader1 = new Header(new QName("uri:singz.ws.sample", "soapheader1"), "SOAP Header Message 1", new JAXBDataBinding(String.class));
Header testSoapHeader2 = new Header(new QName("uri:singz.ws.sample", "soapheader2"), "SOAP Header Message 2", new JAXBDataBinding(String.class));

headersList.add(testSoapHeader1);
headersList.add(testSoapHeader2);

// Add SOAP headers to the web service request
proxy.getRequestContext().put(Header.HEADER_LIST, headersList);

More on this @ http://cxf.apache.org/faq.html#FAQ-HowcanIaddsoapheaderstotherequest%2Fresponse%3F