​x
private final static String UNKNOWN = "unknown";
    public static String getIPAddress(HttpServletRequest request) {
        Predicate<String> predicate = ip -> StringUtils.isBlank(ip) || UNKNOWN.equalsIgnoreCase(ip);

        String IPAddress = request.getHeader("x-forwarded-for");
        if (predicate.test(IPAddress)) {
            IPAddress = request.getHeader("Proxy-Client-IP");
        }
        if (predicate.test(IPAddress)) {
            IPAddress = request.getHeader("WL-Proxy-Client-IP");
        }
        if (predicate.test(IPAddress)) {
            IPAddress = request.getHeader("HTTP_CLIENT_IP");
        }
        if (predicate.test(IPAddress)) {
            IPAddress = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (predicate.test(IPAddress)) {
            IPAddress = request.getHeader("X-Real-IP");
        }
        if (predicate.test(IPAddress)) {
            IPAddress = request.getRemoteAddr();
        }
        if (UNKNOWN.equalsIgnoreCase(IPAddress)) {
            return null;
        } else if (StringUtils.isBlank(IPAddress)) {
            return null;
        }
        return IPAddress.split(",")[0];
    }