public static String getIp(){
if(null == Mvcs.getReq()){
return "";
}
return Lang.getIP(Mvcs.getReq());
}

public static void main(String[] args) {
    System.out.println(getIp());
}

日志显示：2017-08-07 16:07:30,970 org.nutz.castor.Castors.reload(Castors.java:115) DEBUG - Using 95 castor for Castors