@RequestMapping(value = "c_rewrite.do")
 public String reWriteComment(int commentNo, String commentContent) {
   if (service.reWriteComment(commentNo, commentContent)) {
     int articleNo = service.readComment(commentNo).getArticleNo();
     String result = "redirect:read.do?articleNo=" + articleNo;
     return result;
   } else {
     return "redirect:error.do";
   }
 }