Remove elements greater than a threshold in ArrayList

[Duy Dinh]

public static int[] removeElementsGreaterThanThreshold(
        ArrayList<Integer> a, int threshold) {

    // temporary array of the same size
    int[] b = new int[a.size()];
    Collections.sort(a);

    int bIndex = 0;
    // browse 'a' and collect elements that are not greater than the threshold into b
    for (int aIndex = 0; aIndex < a.size(); aIndex++) {
        if (a.get(aIndex) < threshold) {
            b[bIndex] = a.get(aIndex);
            bIndex++;
        }
    }

    // copy elements in temporary elements from index 0 to bIndex
    int[] result = Arrays.copyOfRange(b, 0, bIndex);

    return result;
}