A concurrent random UUID generator

ConcurrentUUIDGenerator.java

public class ConcurrentUUIDGenerator {
  
  public static UUID randomUUID() {
        final Random rnd = ThreadLocalRandom.current();
        long mostSig  = rnd.nextLong();
        long leastSig = rnd.nextLong();

        // Identify this as a version 4 UUID, that is one based on a random value.
        mostSig &= 0xffffffffffff0fffL;
        mostSig |= 0x0000000000004000L;

        // Set the variant identifier as specified for version 4 UUID values.  The two
        // high order bits of the lower word are required to be one and zero, respectively.
        leastSig &= 0x3fffffffffffffffL;
        leastSig |= 0x8000000000000000L;

        return new UUID(mostSig, leastSig);
    }
  
}