How make post in spring mvc

How make for return post in my method authenticates.? I like to post to authenticate (method default in spring mvc for authenticate) and before add validate if user is active.

@RequestMapping(value = "/signin", method = RequestMethod.POST)
public ModelAndView authenticates(
        @RequestParam("username") String login,
        @RequestParam("password") String password,
        @RequestParam("_spring_security_remember_me") String remember,
        @RequestParam("_csrf") String csrf,
        RedirectAttributes ra
        ) throws Exception {

    ModelAndView model = new ModelAndView();
    Account account = accountService.findByLogin(login);


    if (!account.isActive()) {  
        MessageHelper.addErrorAttribute(ra, "signin.errorUserDown", login, login);
        model.setViewName("redirect:/signin");
        return model;
        //return "redirect:/signin";
    }


    //userService.loadUserByUsername(login);
    //userService.signin(account);


    //model.addObject("submit");
    model.addObject("username", login);
    model.addObject("password", password);
    model.addObject("_spring_security_remember_me", remember);
    model.addObject("_csrf", csrf);
    model.setViewName("signin/signinValidate");

    return model;
    //return "authenticate";
}