Play 1.3: single POST action for different request formats

[Golden Eye]

What is the best way to handle different request formats for a single POST action.

So let's assume:

- we have a POST route for adding a single user (e. g. a registration)

- we have a web frontend that sends the user data as html/form data

- we have a mobile app that sends the user data as json or xml or whatever

How to do that in Play 1.3? 

I have read that in newer versions of Play there is a default body parser which is able to handle different request content types and I know that you can define different response content types by using different templates (e. g. xml or json).

I think there should be only one route, e. g. 

POST "user/add" UserController.createUser

I guess it would be rather bad to define different routes for each request format (e. g. "user/add/json" and "user/add/formdata" and "user/add/xml").

So a solution could be to use a single route and the controller determines which request format is used.

But how to do that in play and is this a reasonnable solution?

Would be happy about a discussion and proposals.