public static String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            ip = request.getHeader("Proxy-Client-IP");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            ip = request.getHeader("WL-Proxy-Client-IP");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            ip = request.getRemoteAddr();
        return ip;
    }