I have a Web Service that needs an optional soap header on its methods, but I don't want to have it required(i.e. nullable ).  The reason for this is because my service will be deployed to multiple environments, some of which will require the header while others will not.

Is it possible to use Java annotations to mark a soap method's header parameter as optional?  If not, can it be accomplished via WSDL modification?

Or is the "correct" way to accomplish this by not defining the header in the WSDL, but instead to tell the clients to send the header with mustUnderstand="0".