Integer array [][] = new Integer[testing.size()][];

    for (int y = 0; y < testing.size(); y++)
    {
        ArrayList<Integer> testing2 = square.get(y);
        array[y] = testing2.toArray(new Integer [testing2.size()]);
    }
}

Integer array [][] = new Integer[testing.size()][];

    for (int y = 0; y < testing.size(); y++) {
        // list of integers
        List<Integer> testing2 = square.get(y);
        Integer[] testingArray = testing2.toArray(new Integer [testing2.size()]);
        array[y] = testing2.toArray(new Integer [testing2.size()]);
    }
}