根据request获取请求客户端的外网ip

//根据request获取外网ip
private static String getRemoteIp(HttpServletRequest request) {
//x-forwarded-for:代表客户端，也就是HTTP的请求端真实的IP，只有在通过了HTTP代理或者负载均衡服务器时才会添加该项
String ip = request.getHeader("x-forwarded-for");

        //Proxy-Client-IP和WL-Proxy-Client-IP: 只有在Apache（Weblogic Plug-In Enable）+WebLogic搭配下出现，
        // 其中“WL”就是WebLogic的缩写 访问路径是:Client -> Apache WebServer + Weblogic http plugin ->
        // Weblogic Instances
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();
        }
//        ip = "61.51.253.90";
//        ip = "218.25.19.153";
        //0:0:0:0:0:0:0:1: IPV6的形式,win7下可能会出现
return ip.equals("0:0:0:0:0:0:0:1") ? "127.0.0.1" : ip;
    }