toast(redirectAttributes, message(Consts.Messages.DELETE_SUCCESSFULLY));求解释

Question

@RequestMapping(value = "/{tagId}/delete", method = RequestMethod.POST)    public String delete(@PathVariable String tagId, RedirectAttributes redirectAttributes) {        try {            tagRepository.delete(tagId);            toast(redirectAttributes, message(Consts.Messages.DELETE_SUCCESSFULLY));        } catch (DataIntegrityViolationException e) {            toast(redirectAttributes, message(Consts.Messages.DELETE_TAG_FAILD));        }        return "redirect:/tags/index";    }