Empirically tests degree of uniqueness when converting UUIDs to hashcode values

UUIDToHashcodeUniquenessTestMain

package collisions.test;

import java.util.HashSet;
import java.util.Set;
import java.util.UUID;

public class UUIDToHashcodeUniquenessTestMain {

	private final static int num_of_users = 1000 * 1000;
	private final static int num_of_stacks = 50;

	public static void main(String[] args) {
		int collisions = 0;
		for (int i = 0; i < num_of_users; i++) {
			collisions += calcCollisionsForUser();
		}
		System.out.println("Had " + collisions + " collisions for " + num_of_users + " users");
	}

	private static int calcCollisionsForUser() {
		int collisions = 0;
		Set<Integer> uuidSet = new HashSet<Integer>(num_of_stacks * 2);
		for (int i = 0; i < num_of_stacks; i++) {
			String uuid = UUID.randomUUID().toString();
			Integer uuidHashcode = uuid.hashCode();
			if (uuidSet.contains(uuidHashcode)) {
				collisions++;
			}
			uuidSet.add(uuidHashcode);
		}
		return collisions;
	}
}