While the UUIDs are not guaranteed to be unique, the probability of a duplicate is extremely low. See Random UUID probability of duplicates. For your application, it makes sense to use the UUID, but you may want to deal with the extremely rare condition, just in case.

Is Java UUID unique?

UUIDs are handy for giving entities their own special names, for example, in a database. There are several ways to generate them, including methods based on time, MAC addresses, hashes, and random numbers, but they make the same promise: no two are identical. Each one is unique across space and time.

Is UUID really unique?

When generated according to the standard methods, UUIDs are, for practical purposes, unique. Their uniqueness does not depend on a central registration authority or coordination between the parties generating them, unlike most other numbering schemes.