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cowtowncoder / java-uuid-generator

Java Uuid Generator (JUG) is a Java library for generating all standard UUID versions (v1 - v7)
Apache License 2.0
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TimeBasedGenerator factory method that defaults to a sensible choice of interface #44

Closed pgalbraith closed 2 years ago

pgalbraith commented 2 years ago

egressTimeBasedGenerator() factory method that will make an educated guess as to which interface to use, by trying to find the interface corresponding to the local default network route

cowtowncoder commented 2 years ago

@pgalbraith Apologies for the very slow follow up. This looks good; I added couple of notes but would be happy to merge this in master for inclusion in 4.1.0 -- there will be a few other additions (for new UUID variants, 6, 7 and 8).

One other thing: if you want, it'd be great to add a note on README.md for this new added generator method, so others find it more easily.

cowtowncoder commented 2 years ago

I think this is fine; I can do minor clean up on my own. :)

cowtowncoder commented 2 years ago

Hmmmh. A bunch of unit tests fail for me locally, will revert.

cowtowncoder commented 2 years ago

Ok so I had to revert this but would like to try again. But not quite sure how to resurrect merged PR...

cowtowncoder commented 2 years ago

I think the problem was that refactoring of fromInterface() returned null but caller did not check for null case. So depending on order of interfaces returned it could (and did, in my case) result in NPE. Relatively easy to check, I see if I can just manually merge changes.

cowtowncoder commented 2 years ago

Ok, so, unfortunately this simply does not work on my machine (macos on Mac mini); egress accessors return null (or before adding checks, NPE). I think there is also a small but significant problem with missing null handling, added a note above.

So at this point I cannot really merge this. The idea sounds reasonable so I hope this can be worked to pass tests on different machines with differing interfaces.

pgalbraith commented 2 years ago

Ok thanks for taking a look, hopefully I can take a look as well this weekend and see where it went wrong.

pgalbraith commented 2 years ago

@cowtowncoder ah yes I see the problem, back when I wrote this it was on a different machine, and that machine must have been returning the default interface as the first one in the loop, and things worked fine. My new machine doesn't do that, i have the same problem as you did.

cowtowncoder commented 2 years ago

@pgalbraith ok yes that makes sense.