Java 获取请求 ip 失败

同一个方法，在接口 1、A 服务器上获取不了 ip，在接口 2、A 服务器上能获取，在接口 1、B 服务器上能获取 真是奇了怪了 方法如下

public String getIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");

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