Java 獲取當前項目所在服務器的 IP 地址

java中獲取當前服務器地址主要使用到InetAddress這個類

public static void main(String[] args) {
        try {
            //用 getLocalHost() 方法創建的InetAddress的對象
            InetAddress address = InetAddress.getLocalHost();
            System.out.println(address.getHostName());//主機名
            System.out.println(address.getCanonicalHostName());//主機別名
            System.out.println(address.getHostAddress());//獲取IP地址
            System.out.println("===============");
            
            //用域名創建 InetAddress對象
            InetAddress address1 = InetAddress.getByName("www.wodexiangce.cn");
            //獲取的是該網站的ip地址，如果我們所有的請求都通過nginx的，所以這里獲取到的其實是nginx服務器的IP地址
            System.out.println(address1.getHostName());//www.wodexiangce.cn
            System.out.println(address1.getCanonicalHostName());//124.237.121.122
            System.out.println(address1.getHostAddress());//124.237.121.122
            System.out.println("===============");
            
            //用IP地址創建InetAddress對象
            InetAddress address2 = InetAddress.getByName("220.181.111.188");
            System.out.println(address2.getHostName());//220.181.111.188
            System.out.println(address2.getCanonicalHostName());//220.181.111.188
            System.out.println(address2.getHostAddress());//220.181.111.188
            System.out.println("===============");
            
            //根據主機名返回其可能的所有InetAddress對象
            InetAddress[] addresses = InetAddress.getAllByName("www.baidu.com");
            for (InetAddress addr : addresses) {
                System.out.println(addr);
                //www.baidu.com/220.181.111.188
                //www.baidu.com/220.181.112.244
            }
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
    }

如果使用了反向代理，這種獲取方式顯然是不准確的，我們采用的方法是新建一個java類，里面配的是當前服務器的IP地址（也就是說這個類在每個節點服務器上部署的是不同的），程序里用的話直接獲取這個工具類就可以了，雖然方法有點笨，但是解決問題了。

public class CommonServerIP {
    /**
     * #######################################################################
     * ###############這個類主要是保存常用的一些固定的服務器IP#####################
     * ####################################################################### 
     */
     public static String CURRENT_SERVER="124.237.121.46";//當前服務器的ip地址
}

根據HttpServletRequest對象獲取ip

    public String getIpAddress(HttpServletRequest request) {
        // 獲取請求主機IP地址,如果通過代理進來，則透過防火牆獲取真實IP地址
        try {
            String ip = request.getHeader("X-Forwarded-For");

            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                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.getHeader("HTTP_CLIENT_IP");
                }
                if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getHeader("HTTP_X_FORWARDED_FOR");
                }
                if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
                    ip = request.getRemoteAddr();
                }
            } else if (ip.length() > 15) {
                String[] ips = ip.split(",");
                for (int index = 0; index < ips.length; index++) {
                    String strIp = ips[index];
                    if (!("unknown".equalsIgnoreCase(strIp))) {
                        ip = strIp;
                        break;
                    }
                }
            }
            return ip;
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
    }