Optional RequestParam in Spring MVC Controller

I have below code

public ModelAndView springController(@ModelAttribute("param1") Object param1,
        @RequestParam(value = "param2", required = false) Object param2,
        BindingResult bindingResult) 

I am not submitting any value from JSP for param2. I have also provided required=false for param2. But when I hit the submit button it gives 400 Bad Request error.