Java: Randomly generate distinct names

Question

I need to generate 10,000 unique identifiers in Java. The identifiers should be a mixture of numbers and letters and less than 10 characters each. Any ideas? Built in librar

Answer 1

You could try

Random rand = new Random();
Set<String> words = new HashSet<String>();
while(words.size() < 10000) 
    words.add(Long.toString(Math.abs(rand.nextLong() % 3656158440062976L), 36)));

The long constant is just enough for 10 digit, base 36 numbers.

Answer 2

Why not use java.util.UUID? It is guaranteed to generate unique identifiers, and it is as standard as it gets :-).