How to get client Ip Address in Java HttpServletRequest

Question

I am trying to develop a Java web application (Servlet) which I need to get clients IP address.

Following is my code so far:

Answer 1

Try this one. for all condition

private static final String[] HEADERS_TO_TRY = {
            "X-Forwarded-For",
            "Proxy-Client-IP",
            "WL-Proxy-Client-IP",
            "HTTP_X_FORWARDED_FOR",
            "HTTP_X_FORWARDED",
            "HTTP_X_CLUSTER_CLIENT_IP",
            "HTTP_CLIENT_IP",
            "HTTP_FORWARDED_FOR",
            "HTTP_FORWARDED",
            "HTTP_VIA",
            "REMOTE_ADDR" };

private String getClientIpAddress(HttpServletRequest request) {
    for (String header : HEADERS_TO_TRY) {
        String ip = request.getHeader(header);
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            return ip;
        }
    }

    return request.getRemoteAddr();
}