问如何找到“正确的”IP地址？

EN

public enum IpAddressHelper
{

    X_FORWARDED_FOR("X-Forwarded-For"),
    PROXY_CLIENT_IP("Proxy-Client-IP"),
    WL_PROXY_CLIENT_IP("WL-Proxy-Client-IP"),
    HTTP_CLIENT_IP("HTTP_CLIENT_IP"),
    HTTP_X_FORWARDED_FOR("HTTP_X_FORWARDED_FOR");

    private static final Logger LOGGER = LoggerFactory.getLogger(IpAddressHelper.class);
    private static final String REMOTE_ADDR = "REMOTE_ADDR";
    private String key;

    /**
     * @param key
     */
    IpAddressHelper(String key)
    {
        this.key = key;
    }

    /**
     * @return the key
     */
    public String getKey()
    {
        return key;
    }

    public static String getClientIpAddr(HttpServletRequest request)
    {

        String ip = null;
        for (IpAddressHelper header : IpAddressHelper.values())
        {
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getHeader(header.getKey());
                LOGGER.info("tried:" + header);
            }
        }

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

        return ip;
    }

    public static String getClientIpAddr(Map<String, String> requestHeaders)
    {
        String ip = null;
        for (IpAddressHelper header : IpAddressHelper.values())
        {
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = requestHeaders.get(header.getKey());
                LOGGER.info("tried:" + header);
            }
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
        {
            ip = requestHeaders.get(REMOTE_ADDR);
        }

        return ip;
    }
}