/**
   * 得到请求的IP地址
   * 
   * @param request
   * @return
   */
  public static String getIp(HttpServletRequest request) {
    String ip = request.getHeader("X-Real-IP");
    if (StringUtils.isBlank(ip)) {
      ip = request.getHeader("Host");
    }
    if (StringUtils.isBlank(ip)) {
      ip = request.getHeader("X-Forwarded-For");
    }
    if (StringUtils.isBlank(ip)) {
      ip = "0.0.0.0";
    }
    return ip;
  }