Java获取外网IP地址，常用于用户访问路径分析

获取外网IP

/**
 * 获取外网IP
 * @param request
 * @return
 */
public static String getIpAddr(HttpServletRequest request) { 
   String ipAddress = null;
   // ipAddress = this.getRequest().getRemoteAddr();
   ipAddress = request.getHeader("x-forwarded-for");
   if (ipAddress == null || ipAddress.length() == 0
         || "unknown".equalsIgnoreCase(ipAddress)) {
      ipAddress = request.getHeader("Proxy-Client-IP");
   }
   if (ipAddress == null || ipAddress.length() == 0
         || "unknown".equalsIgnoreCase(ipAddress)) {
      ipAddress = request.getHeader("WL-Proxy-Client-IP");
   }
   if (ipAddress == null || ipAddress.length() == 0
         || "unknown".equalsIgnoreCase(ipAddress)) {
      ipAddress = request.getRemoteAddr();
      if (ipAddress.equals("127.0.0.1")) {
         // 根据网卡取本机配置的IP
         InetAddress inet = null;
         try {
            inet = InetAddress.getLocalHost();
         } catch (UnknownHostException e) {
            e.printStackTrace();
         }
         ipAddress = inet.getHostAddress();
      }

   }

   // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
   if (ipAddress != null && ipAddress.length() > 15) { // "***.***.***.***".length()
                                          // = 15
      if (ipAddress.indexOf(",") > 0) {
         ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
      }
   }
   return ipAddress;
   }