Unique Random Int Numbers in Java

UniqueIntRandom.java

public class UniqueIntRandom {

    private ArrayList<Integer> numberStore;

    public UniqueIntRandom(int startingNum, int endNum) {
        numberStore = new ArrayList<>();
        initRandomNumbers(startingNum, endNum);
    }

    public UniqueIntRandom(int endNum) {
        numberStore = new ArrayList<>();
        initRandomNumbers(1, endNum);
    }

    private void initRandomNumbers(int startingNum, int endNum) {
        for (int i = startingNum; i <= endNum; i++) {
            numberStore.add(i);
        }
        Collections.shuffle(numberStore);
    }

    public int nextUniqueRandom() throws IndexOutOfBoundsException {
        int temp = numberStore.get(0);
        numberStore.remove(0);
        return temp;
    }
}