title: Supporting multiple xsd versions
body: <p>Let me explain my scenario
  I have a web application that takes xml requests and responds.
  I have used jaxb to parse the request, convert it to my applications dao object, process the request and then reconvert the dao result to jaxb object and return that.
  Now i have to support multiple versions (different xml versions can come as request and i have to respond with suitable xml response).
  I generate java files for jaxb object -> dao object convertor and reverse.
  Problem is that before conversion to my dao object the jaxb object is created and then validated before passing it to my convertor. I am not sure what design pattern to apply here.
  Might be adaptor pattern. Please suggest?
  Also throw light if i may have to generate the jaxb marshalling and un-marshalling code too?</p>