When you call marshalSendAndReceive method of class WebServiceTemplate with a request callback to add a SoapAction (see https://docs.spring.io/spring-ws/docs/current/reference/html/#_using_webservicemessagecallback) :

• if request payload is not null, SoapAction is well added
• if request payload is null, SoapAction is not added.

So when request payload is null (web service soap without parameter), we are unable to add SoapAction.

Maybe, I am wrong and there is another way to do this.

I join a patch to help understanding.

nullrequestwithsoapaction.patch