Springboot obtains the client IP address tool class

The most comprehensive tool method to obtain the real IP address of the client, compatible with the proxy and k8s cluster to obtain IP

注意：如果使用代理，比如nginx一定要配置请求头的转发

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;



public class IPUtils {
    
    
    private static Logger logger = LoggerFactory.getLogger(IPUtils.class);
    private static final String IP_UTILS_FLAG = ",";
    private static final String UNKNOWN = "unknown";
    private static final String LOCALHOST_IP = "0:0:0:0:0:0:0:1";
    private static final String LOCALHOST_IP1 = "127.0.0.1";

    /**
     * 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 {
    
    
            //以下两个获取在k8s中，将真实的客户端IP，放到了x-Original-Forwarded-For。而将WAF的回源地址放到了 x-Forwarded-For了。
            ip = request.getHeader("X-Original-Forwarded-For");
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("X-Forwarded-For");
            }
            //获取nginx等代理的ip
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("x-forwarded-for");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            //兼容k8s集群获取ip
            if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
    
    
                ip = request.getRemoteAddr();
                if (LOCALHOST_IP1.equalsIgnoreCase(ip) || LOCALHOST_IP.equalsIgnoreCase(ip)) {
    
    
                    //根据网卡取本机配置的IP
                    InetAddress iNet = null;
                    try {
    
    
                        iNet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
    
    
                        logger.error("getClientIp error: {}", e);
                    }
                    ip = iNet.getHostAddress();
                }
            }
        } catch (Exception e) {
    
    
            logger.error("IPUtils ERROR ", e);
        }
        //使用代理，则获取第一个IP地址
        if (!StringUtils.isEmpty(ip) && ip.indexOf(IP_UTILS_FLAG) > 0) {
    
    
            ip = ip.substring(0, ip.indexOf(IP_UTILS_FLAG));
        }

        return ip;
    }

}