String[] arr = new String[]{"one","two","three"};
<ArrayList<String[]> arrlist = new ArrayList<String[]>();
arrlist.add(arr);
// Declare it
List<Integer>[] array = new List<Integer>[5];
// Put something into an array element
array[3] = new ArrayList<Integer>();
// Access an element -- it's a List
List<Integer> list = array[3];
Integer x = list.get(0);