There is no shortcut for converting from int[] to List<Integer> as Arrays.asList does not deal with boxing and will just create a List<int[]> which is not what you want. You have to make a utility method.
int[] ints = {1, 2, 3};
List<Integer> intList = new ArrayList<Integer>();
for (int i : ints)
{
intList.add(i);
}
Because this process is so stupid, I highly recommend not to do so in interview unless you are sure that what you are doing.