IP地址获取

如果是为了记录IP访问记录，则可采用如下方法（包含了大部分服务代理）：

public String getIpAddress(HttpServletRequest request) {

        String ip = null;

        //X-Forwarded-For：Squid 服务代理
        String ipAddresses = request.getHeader("X-Forwarded-For");
        String unknown = "unknown";
        if (ipAddresses == null || ipAddresses.length() == 0 || unknown.equalsIgnoreCase(ipAddresses)) {
            //Proxy-Client-IP：apache 服务代理
            ipAddresses = request.getHeader("Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || unknown.equalsIgnoreCase(ipAddresses)) {
            //WL-Proxy-Client-IP：weblogic 服务代理
            ipAddresses = request.getHeader("WL-Proxy-Client-IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || unknown.equalsIgnoreCase(ipAddresses)) {
            //HTTP_CLIENT_IP：有些代理服务器
            ipAddresses = request.getHeader("HTTP_CLIENT_IP");
        }

        if (ipAddresses == null || ipAddresses.length() == 0 || unknown.equalsIgnoreCase(ipAddresses)) {
            //X-Real-IP：nginx服务代理
            ipAddresses = request.getHeader("X-Real-IP");
        }

        //有些网络通过多层代理，那么获取到的ip就会有多个，一般都是通过逗号（,）分割开来，并且第一个ip为客户端的真实IP
        if (ipAddresses != null && ipAddresses.length() != 0) {
            ip = ipAddresses.split(",")[0];
        }

        //还是不能获取到，最后再通过request.getRemoteAddr();获取
        if (ip == null || ip.length() == 0 || unknown.equalsIgnoreCase(ipAddresses)) {
            ip = request.getRemoteAddr();
        }
　　　　　return ip;
    }

如果是用于IP白名单设置，则可采用如下方法：

    @Value("#{'${ip.free.path}'.split(',')}")
    private List<String> ipFreePath;

    public boolean isFreeIp(HttpServletRequest request) {
　　　　　//无法伪造
        String ip = request.getRemoteAddr();
        if (ipFreePath.contains(ip)) {
            return true;
        }
        return false;
    }