获得访问者真实的IP地址

public static String getClientIpAddr(HttpServletRequest request) {
        String ipAddress = null;
        ipAddress = request.getHeader("x-forwarded-for");
        if (ipAddress == null || ipAddress.length() == 0
                || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length() == 0
                || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length() == 0
                || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
            if (ipAddress.equals("127.0.0.1")) {
                // 根据网卡取本机配置的IP
                InetAddress inet = null;
                try {
                    inet = InetAddress.getLocalHost();
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                }
                ipAddress = inet.getHostAddress();
            }
        }
        // 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
        if (ipAddress != null && ipAddress.length() > 15) {  
            if (ipAddress.indexOf(",") > 0) {
                ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
            }
        }
         
        return ipAddress;
    }