Java UUID string representation natural ordering

Question

Say I have two UUID instances:

uuid1 = UUID.randomUUID();
uuid2 = UUID.randomUUID();

If those two compare such that uuid1 is less than uuid2 i.e.,

uuid1.compareTo(uuid2) // -1

is it always true that their string representations will compare to give the same result, i.e.,

uuid1.toString().compareTo(uuid2.toString()) // -1 ????

Hermann Hans · Accepted Answer · 2010-03-02 15:42:16Z

9

In short, no. Here's a quick counter-example of two UUIDs for which the assertion does not hold:

Using the compareTo from UUID you get -1, while compareTo from the String results in 43.

answered Mar 2, 2010 at 15:42

Hermann Hans

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2 Comments

+1; from reading the API and the RFC, I would have expected consistent behaviour, though...

See bugs.sun.com/bugdatabase/view_bug.do?bug_id=7025832; Oracle will not fix the implementation and will probably not even admit that the Javadoc is wrong.