Hello friends, sometimes you come across with this very unexpected exception.

For eg: In the given code, after execution this exception occurs..

@RequestMapping(value = "addUser")
    public String addUser(@ModelAttribute("userForm") UserForm userForm,
            ModelMap map, BindingResult results) {

        if (results.hasErrors()) {
            return "add_user_form";
        }

        return "add_user_success";
    }
//...
}

Exception: java.lang.IllegalStateException: Errors/BindingResult argument declared without preceding model attribute.

Solution: Well basically, Spring expects the BindingResult attribute to be present right after your Model attribute. So if we change the above controller method to:

RequestMapping(value = "addUser")
public String addUser(@ModelAttribute("userForm") UserForm userForm,
        BindingResult results, ModelMap map) 

This will solve the error.