In order to get a unique machine identifier I have used
hostName = InetAddress.getLocalHost().getHostName();
Which works but it a bit clumsy. Should really look for a better way.
A trivial way of acheiving the same things would be to get the IP address and removed the dots so 220.127.116.11 = 133231212123.
Otherwise it is possible to to convert it to a decimal http://www.mkyong.com/java/java-convert-ip-address-to-decimal-number/