Java獲取ip地址，穿透部分代理訪問

//使用apache的String工具類
import org.apache.commons.lang3.StringUtils;
//代理請求頭字段
private static String headerIpFields[] = {"x-forwarded-for", "PRoxy-Client-IP", "WL-Proxy-Client-IP", "HTTP_CLIENT_IP", "HTTP_X_FORWARDED_FOR", "X-Real-IP"};

/**
 * 獲取id地址，透明代理也能看出來
 *
 * @param request 請求
 * @return ip地址
 */
public static String getRemoteIp(HttpServletRequest request) {
    //正常獲取ip地址
    String ip = request.getRemoteAddr();
    if (isIpValid(ip)) {
        return ip;
    }
    //獲取代理中的ip地址
    for (String headerIpField : headerIpFields) {
        ip = request.getHeader(headerIpField);
        if (isIpValid(ip)) {
            return ip;
        }
    }
    return null;
}

/**
 * 判斷ip是否有效
 *
 * @param ip ip地址
 * @return 是否有效
 */
private static boolean isIpValid(String ip) {
    return !(StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip));
}