Java 获取当前项目所在服务器的 IP 地址

java中获取当前服务器地址主要使用到InetAddress这个类

public static void main(String[] args) {
        try {
            //用 getLocalHost() 方法创建的InetAddress的对象
            InetAddress address = InetAddress.getLocalHost();
            System.out.println(address.getHostName());//主机名
            System.out.println(address.getCanonicalHostName());//主机别名
            System.out.println(address.getHostAddress());//获取IP地址
            System.out.println("===============");
            
            //用域名创建 InetAddress对象
            InetAddress address1 = InetAddress.getByName("www.wodexiangce.cn");
            //获取的是该网站的ip地址，如果我们所有的请求都通过nginx的，所以这里获取到的其实是nginx服务器的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地址创建InetAddress对象
            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("===============");
            
            //根据主机名返回其可能的所有InetAddress对象
            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，这种获取方式显然是不准确的，我们采用的方法是新建一个java类，里面配的是当前服务器的IP地址（也就是说这个类在每个节点服务器上部署的是不同的），程序里用的话直接获取这个工具类就可以了，虽然方法有点笨，但是解决问题了。

public class CommonServerIP {
    /**
     * #######################################################################
     * ###############这个类主要是保存常用的一些固定的服务器IP#####################
     * ####################################################################### 
     */
     public static String CURRENT_SERVER="124.237.121.46";//当前服务器的ip地址
}

根据HttpServletRequest对象获取ip

    public String getIpAddress(HttpServletRequest request) {
        // 获取请求主机IP地址,如果通过代理进来，则透过防火墙获取真实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 "";
        }
    }