[masijade]

You don't. You use the actual key.

[masijade]

uhm get(key)? see the API docs.

[cfoley]

As masijade says, get(key) is the direct way to access the elements.

If this isn't fulfilling your needs maybe you could describe the task you are trying to solve. Gaining access the the Hashtable's underlying array is unlikely to be a good solution so understanding your task would help us suggest a different one.

[masijade]

So get the keyset as a set, call toArray on that, and pull keys out of that array.

[cfoley]

I'd go with the keySet() technique too. If the toArray bothers you, use an iterator to get to the generated index:

int requiredIndex = /*someRandomNumber*/;
assert requiredIndex < map.size();
Set<K> keys = map.keySet();
Iterator<K> = it = keys.iterator();
for(int i = 0; i < requuiredIndex; i++) {
  it.next();
}
K randomKey = it.next();

If it seems wasteful using the keySet technique, try it out and see if it really is slow. If you find it too slow after testing, consider keeping an ArrayList of keys separately. Best to avoid this though. This is where it becomes easy to introduce bugs.