java-code:

public String getRemoteIP(HttpServletRequest request) {
        String clientIp = request.getHeader("x-forwarded-for");
        if (clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
            clientIp = request.getHeader("Proxy-Client-IP");
        }

        if (clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
            clientIp = request.getHeader("WL-Proxy-Client-IP");
        }

        if (clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
            clientIp = request.getRemoteAddr();
        }

        return clientIp;
    }