With Spring 2.0 I like how it allows you to configure different binding mechanisms and marshallers for the request and response to a single operation. In my case, I am using the @XPathParam configuration to parse the request to my operation and using a custom Stax marshaller for the response. Below is my custom marshaller configuration in my spring context file. As you can see below, I have no Unmarshaller configured on MarshallingPayloadMethodProcessor because I am not doing any unmarshalling in my service using the Unmarshaller interface. The issue is that MarshallingPayloadMethodProcessor requires both a marshaller and unmarshaller be set and will throw an exception if they are not both set.
Would it possible to change the MarshallingPayloadMethodProcessor's validation logic so it only checks that at least a marshaller or an unmarshaller is set instead of always requiring both?
<property name="marshaller" ref="pingMarshaller" />
<bean id="pingMarshaller" class="...