org.davesag.generica.util
Class UuId

java.lang.Object
  org.davesag.generica.util.UuId

public class UuId

extends Object

Generates a universally unique id number.

Since:

Generica 1.0

Version:

CVS Revision $Id: UuId.java,v 1.4 2004/03/30 10:12:59 norm Exp $

Author:

Dave Sag http://www.davesag.com

Constructor Summary

UuId()

Method Summary

static long

generate() Generate a Unique Universal Id Number.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UuId

public UuId()

Method Detail

generate

public static long generate()

Generate a Unique Universal Id Number. It does this based on a random number, with an appended system time in milliseconds, and then an appended number derived the host IP numbers associated with localhost. This ensures that within any millisecond interval, for a particular host machine, there is a 1/2^62 chance of the uuid's ever repeating. It could be enhanced to actually check for repition but honestly it's overkill I think. I have tested this on over 1,000,000 iterations and have never had a repeat.

Returns:

the number.