title: Spring MVC- Binding handler method parameter to type selected at runtime
body: <p>Similar to <a href="https://stackoverflow.com/q/16598571/1503554">Spring MVC abstract class binding</a>, I have handler methods with an @ModelAttribute parameter which is an interface. Based on some of the properties of the incoming request, I want to programmatically select an implementation to instantiate and then bind it to the request body using whatever Spring has down in its guts for marshalling into objects.</p>
  
  <p>Is this possible and what Spring components would I need to make use of to achieve it?</p>