private boolean checkInputErrors(User user, Model model) { boolean isErrorInput = false; if (!user.getEmail().matches(".+@.+\\..+") || user.getEmail().length() > 75) { model.addAttribute("notCorrectEmail", true); isErrorInput = true; } if (!user.getUsername().matches("[a-zA-Zà-ÿÀ-ß0-9_]+") || user.getUsername().length() > 30) { model.addAttribute("notCorrectUsername", true); isErrorInput = true; } else { if (userService.isRegistered(user.getUsername())) { model.addAttribute("usernameAlreadyRegistered", true); isErrorInput = true; } } if (!user.getPassword().matches("[a-zA-Zà-ÿÀ-ß0-9_]+") || user.getPassword().length() > 30) { model.addAttribute("notCorrectPassword", true); isErrorInput = true; } return isErrorInput; }