content: package com.smart.common.util;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.util.StringUtils;
  import org.springframework.web.context.request.RequestContextHolder;
  import org.springframework.web.context.request.ServletRequestAttributes;
  
  import javax.servlet.http.HttpServletRequest;
  /**
   * IP地址
   * 爪哇笔记：https://blog.52itstyle.vip
   */
  public class IPUtils {
  
      private static Logger logger = LoggerFactory.getLogger(IPUtils.class);
  
      /**
       * 获取IP地址
       * 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 = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
          String ip = null;
          try {
              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");
              }
              if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
                  ip = request.getRemoteAddr();
              }
          } 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.length() > 15) {
              if (ip.indexOf(",") > 0) {
                  ip = ip.substring(0, ip.indexOf(","));
              }
          }
          return ip;
      }
  }