从request中获取访问者IP地址

/**

  * 获取访问者IP地址

  */

 public static String getIpAddr(HttpServletRequest request) {

  String 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") || ipAddress.equals("0:0:0:0:0:0:0:1")) {

    // 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;

 }