前言

最近在做一个篮球社交网站，根据系统的设计的需求，为防止用户恶意灌水及发布一些不合规言论，需要记录发表评论的用户的真实IP地址信息。本文记录了JAVA获取真实IP地址的实现方法，如果你的系统也有类似的需要获取用户IP地址的需求，可以参考一下这篇的实现方式。

JAVA获取真实IP地址代码如下：

/**
     * 获取用户真实IP地址
     * 堆代码 duidaima.com
     * @param request
     * @return
     * 
     */
    public static String getAddress(HttpServletRequest request) {
        String ipAddress = request.getHeader("x-forwarded-for");
        if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = request.getRemoteAddr();
            if (ipAddress.equals("127.0.0.1") || ipAddress.equals("0:0:0:0:0:0:0:1")) {
                // 根据网卡取本机配置的IP
                ipAddress = getLocalIP();
            }
        }
        // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
        if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length()
                                                            // = 15
            if (ipAddress.indexOf(",") > 0) {
                ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
            }
        }
        return ipAddress;
    }
 
        /**
     * 获取外网IP
     * 
     * @return
     */
    public static String getIp() {
        String ip = "";
        String chinaz = "http://ip.chinaz.com";
        StringBuilder inputLine = new StringBuilder();
        String read = "";
        URL url = null;
        HttpURLConnection urlConnection = null;
        BufferedReader in = null;
        try {
            url = new URL(chinaz);
            urlConnection = (HttpURLConnection) url.openConnection();
            in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "UTF-8"));
            while ((read = in.readLine()) != null) {
                inputLine.append(read + "\r\n");
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        Pattern p = Pattern.compile("\\<dd class\\=\"fz24\">(.*?)\\<\\/dd>");
        Matcher m = p.matcher(inputLine.toString());
        if (m.find()) {
            String ipstr = m.group(1);
            ip = ipstr;
        }
        return ip;
    }
 
    /**
     * 取当前系统站点本地地址 linux下 和 window下可用
     *
     * @return
     */
    public static String getLocalIP() {
        String sIP = "";
        InetAddress ip = null;
        try {
            // 如果是Windows操作系统
            if (isWindowsOS()) {
                ip = InetAddress.getLocalHost();
            }
            // 如果是Linux操作系统
            else {
                boolean bFindIP = false;
                Enumeration<NetworkInterface> netInterfaces = NetworkInterface.getNetworkInterfaces();
                while (netInterfaces.hasMoreElements()) {
                    if (bFindIP) {
                        break;
                    }
                    NetworkInterface ni = netInterfaces.nextElement();
                    // ----------特定情况，可以考虑用ni.getName判断
                    // 遍历所有ip
                    Enumeration<InetAddress> ips = ni.getInetAddresses();
                    while (ips.hasMoreElements()) {
                        ip = ips.nextElement();
                        if (ip.isSiteLocalAddress() && !ip.isLoopbackAddress() // 127.开头的都是lookback地址
                                && ip.getHostAddress().indexOf(":") == -1) {
                            bFindIP = true;
                            break;
                        }
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (null != ip) {
            sIP = ip.getHostAddress();
        }
        return sIP;
    }
 
    /**
     * 判断当前系统是否是Windows操作系统
     * 
     * @return
     */
    public static boolean isWindowsOS() {
        if ("//".equals(File.separator)) {
            return true;
        } else {
            return false;
        }
    }

以上就是JAVA获取真实IP地址的实现方式，这边获取外网IP的地址调用了第三方网站网站的查询系统，通过正则表达式过滤获取外网的IP地址，这边如果你们有第三方的获取外网IP地址的API接口，则直接调用接口更方便。