code: public void useNewSOAPServiceWithOldClient() throws Exception {
          
          URL wsdlURL = getClass().getResource("/CustomerServiceNew.wsdl");
          com.example.customerservice.CustomerServiceService service = 
              new com.example.customerservice.CustomerServiceService(wsdlURL);
          
          com.example.customerservice.CustomerService customerService = 
              service.getCustomerServicePort();
  
          // The outgoing new Customer data needs to be transformed for 
          // the old service to understand it and the response from the old service
          // needs to be transformed for this new client to understand it.
          Client client = ClientProxy.getClient(customerService);
          addTransformInterceptors(client.getInInterceptors(),
                                   client.getOutInterceptors(),
                                   false);
          
          System.out.println("Using new SOAP CustomerService with old client");
          
          customer.v1.Customer customer = createOldCustomer("Barry Old to New SOAP");
          customerService.updateCustomer(customer);
          customer = customerService.getCustomerByName("Barry Old to New SOAP");
          printOldCustomerDetails(customer);
      }
docs: Old SOAP client uses new SOAP service