Java TreeSet remove duplicates based on object attribute

I wish to use TreeSet to remove duplicate object based on their attributes (here is toString() which return object's name ), here is my code :

Set<Object> s = new TreeSet<>(new Comparator<Object>() {          
            @Override
            public int compare(Object o1, Object o2) {
                if (o1.toString().equals(o2.toString())) {
                    return 0;
                } else {
                    return 1;
                }
            }
        });
s.addAll(listComCopy);
listComCopy.clear();
listComCopy.addAll(s);

listComCopy is a list of object.

It does the work but it only compares consecutive objects on the list, so if i have list(50).equals(list(150)) it will ignore.

Do you have any idea of how can i refactor this code to eliminate all duplicates regardeless their order in the list?

Your compare method does not adhere to the requirements.

See Comparator.compare ...

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

You would be better off using String.compareTo in your compare.

    Set<Object> s = new TreeSet<>(new Comparator<Object>() {
        @Override
        public int compare(Object o1, Object o2) {
            return o1.toString().compareTo(o2.toString());
        }
    });