How to have seven unique number between 0 and 14?

I need to have seven unique number between 0 and 14 (from 0 to 13). I came up with the below code -

private Set<Integer> generateNumber() {
    Set<Integer> randomNumberList = new HashSet<Integer>();

    while (true) {
        if (randomNumberList.size() == 7) {
            break;
        }
        randomNumberList.add(random.nextInt((14 - 0) + 1) + 0);
    }

    return randomNumberList;
}

Is there any better way of doing this? I am not sure whether I should use while true here for this simple thing.