Question

I know that The Treeset Sort the input automatically but don’t accept duplicates.Is there any class Collection in java that allows Duplicate values or objects and Sort the given Input

Answer 1

User List Implementation and sort them using Collection.sort()

List<String> list=new ArrayList<String>();
    list.add("A");
    list.add("C");
    list.add("A");
    list.add("B");
    list.add("A");

    System.out.println(list);
    Collections.sort(list);
    System.out.println(list);

But if you are using you object in collection then Implement Comparable interface and override compare(Object obj,Object obj1) method.

Otherwise you can write your Comparator then pass it to sort method.