How to Sort 2D ArrayList by Only the First Element [duplicate]

Answer 1

Create a custom comparator:

final Comparator> comparator = new Comparator>() {
    public int compare(List pList1, List pList2) {
        return pList1.get(0).compareTo(pList2.get(0));
    }
};
final List> lists = Arrays.asList(
    Arrays.asList("Mike", "(805) 766-4920"),
    Arrays.asList("Emily", "(705) 668-9292", "(705) 555-1060"),
    Arrays.asList("James", "(605) 965-2000")
);
Collections.sort(lists, comparator);
for (List list : lists) System.out.println(list);