How to maintain a Unique List in Java?

Question

How to create a list of unique/distinct objects (no duplicates) in Java?

Right now I am using HashMap to do this as the key is o

Answer 1

I do not know how efficient this is, However worked for me in a simple context.

List<int> uniqueNumbers = new ArrayList<>();

   public void AddNumberToList(int num)
    {
        if(!uniqueNumbers .contains(num)) {
            uniqueNumbers .add(num);
        }
    }