获得客户端真实IP地址

/**
* 获得客户端真实IP地址
*
* @param request
* @return
*/
public static String getIpAddr(HttpServletRequest request) {
String ip = request.getHeader("X-Forwarded-For");
  if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("Proxy-Client-IP");
  }
  if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("WL-Proxy-Client-IP");
  }
  if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("HTTP_CLIENT_IP");
  }
  if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getHeader("HTTP_X_FORWARDED_FOR");
  }
  if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
      ip = request.getRemoteAddr();
  }
return ip;
}