Using of @ModelAttribute

@RequestMapping(value = "/processform", method = RequestMethod.POST)
public String handleForm(@ModelAttribute User user, Model m){
    return "contactSucess";
}

// it works three works
// replace @RequestParam
// do not have use Model
// do not need to create model of user and set it in model.setAttribute("user", user)
// it can be use on top of method

@ModelAttribute
public void commonDataForModel(Model m) {
    m.addAttribute("Header", "0BIT1NP");
    m.addAttribute("Desc", "Paving Digital path of Nepal");
}

// this commonDataForModel will execute before other method
// Set the value for attribute for all methods