第一步：在nginx的location中添加如下配置：

location / {
            proxy_pass   http://127.0.0.1:9999;
            proxy_connect_timeout 180;
            proxy_send_timeout 180;
            proxy_read_timeout 180;
            proxy_set_header Host $host:$server_port;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

第二步：获取真实ip地址

public class IpUtils {

    /**
  * 获取IP地址 * <p>
  * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
  * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址 */
  public static String getIpAddr(HttpServletRequest request) {
        String ip = null;
 try {
            if (request == null) {
                return "";
  }
            ip = request.getHeader("x-forwarded-for");
 if (checkIp(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
  }
            if (checkIp(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
  }
            if (checkIp(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
  }
            if (checkIp(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
  }
            if (checkIp(ip)) {
                ip = request.getRemoteAddr();
 if ("127.0.0.1".equals(ip) || "0:0:0:0:0:0:0:1".equals(ip)) {
               // 根据网卡取本机配置的IP
  ip = getLocalAddr();
  }
            }
        } catch (Exception e) {
            log.error("IPUtils ERROR, {}", e.getMessage());
  }

        //使用代理，则获取第一个IP地址
        if(StringUtils.isEmpty(ip) && ip.length() > 15) {
            if(ip.indexOf(",") > 0) {
            ip = ip.substring(0, ip.indexOf(","));
  }
      }

        return ip;
  }

    private static boolean checkIp(String ip) {
        String unknown = "unknown";
 return StringUtils.isEmpty(ip) || ip.length() == 0 || unknown.equalsIgnoreCase(ip);
  }

   /**
 * 获取本机的IP地址 */  private static String getLocalAddr() {
      try {
         return InetAddress.getLocalHost().getHostAddress();
  } catch (UnknownHostException e) {
         log.error("InetAddress.getLocalHost()-error, {}", e.getMessage());
  }
      return "";
  }
}