docs: public static String getIpAddr(HttpServletRequest request) {
    
          String ip = request.getHeader(WebConstants.HEADER_FROWARDED_FOR);
          if (StringUtils.isBlank(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
              ip = request.getHeader("Proxy-Client-IP");
          }
          if (StringUtils.isBlank(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
              ip = request.getHeader("WL-Proxy-Client-IP");
          }
          if (StringUtils.isBlank(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
              ip = request.getRemoteAddr();
              if (ip.equals(LOCAL_BACK_IP)) {
                  /** 根据网卡取本机配置的IP */
                  ip = getLocalIpAddr();
              }
          }
          /**
           * 对于通过多个代理的情况， 第一个IP为客户端真实IP,多个IP按照','分割
           * x-forwarded-for=192.168.2.22, 192.168.1.92
           */
          if (ip != null && ip.length() > 15) {
          	String[] ips = StringUtils.split(ip, ",");
              for (String _ip : ips) {
              	ip = StringUtils.trimToNull(_ip);
  				if(!UNKNOWN.equalsIgnoreCase(ip)){
  					return ip;
  				}
  			}
          }
          return ip;
      }