My task is - to create a model attribute by given request parameters, to validate it (in same method) and to give it whole to the View.

I was given this code:

//Create the model attribute by request parameters
Promotion promotion = Promotions.get(someRequestParam); 

//Add the attribute to the model
modelMap.addAttribute("promotion", promotion); 

if (!promotion.validate()) {
    BindingResult errors = new BeanPropertyBindingResult(promotion, "promotion");
    errors.reject("promotion.invalid");
    //TODO: This is the part I don't like
    model.put(BindingResult.MODEL_KEY_PREFIX + "promotion", errors);
}

This thing sure works, but that part with creating key with MODEL_KEY_PREFIX and attribute name looks very hackish and not a Spring style to me. Is there a way to make the same thing prettier?