Workarounds for adding new fields to existing output data type in SOAP
jax-ws, soap
Solution
From my personal experience this is still the case. I think your main concern is the versioning methodology. You can look at: http://www.ibm.com/developerworks/webservices/library/ws-version/, or more close to home Web Services API Versioning.
Problem
According to this article about backwards compatibility in SOAP by IBM they state that new fields can not be added to output types without breaking the contract. The relevant snip from the page is from the section titled New, optional fields in an existing data type... You can add an element to an existing complexType as long as you make it optional (using the minOccurs="0" attribute). But be careful. Adding an optional element is a minor change only if its enclosing complexType is received as input to the new service. The new service cannot return a complexType with new fields. If an old client were to receive the new field, the client deserialization would fail because the client would not know about the new field. This was written in 2004 for the WSDL 1.1 spec. Is this still true under current under the WSDL 1.2 spec? Is there no way to define a default behavior of "ignore" for new unknown fields? This statement also seems implementation specific or is that per the spec? I am trying to contend with the issue of evolving a SOAP service that returns complex business objects. New fields will be added as consumers find use cases for them. I would like to avoid having keep N versions of the service around for simply adding new fields.