Right now I have hard coded it for json like the following code snippet.
    @GET @Path("/{id}")
    @Produces({MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML})
    public Response getCustomer(@PathParam("id") String id) {
        Customer c = null;
        Response r = null;
        if(id != null){
            c = fetchCustomer(id);//fetchCustomer will return the customer with id
            Builder ob = Builder.create(c);
            r = Response.ok(ob.deliver(),MediaType.APPLICATION_JSON).build();
        }
        else{
            r = Response.status(400).build();
        }
        return r;
    }
How can I remove the hard coding and give the result in desired format?