@RequestMapping(value = "/mypage/modifytag.do", method = RequestMethod.GET)
  public String modifyTag(
      @RequestParam(value = "tn", required = false) String tn,
      @RequestParam("tagId") int tagId,
      @RequestParam("tagName") String tagName) {
    TagView tagView = tagService.getTag(tagId);
    tagView.setTagName(tagName);
    boolean isTag = tagService.modifyTag(tagView);

    return "redirect:/mypage/managetag.do?tn=" + tn;
  }