Finding Duplicates in Array and printing them only Once

Question

I am trying to loop through my array and find all the numbers that are repeating more than once:

E.G: if there is 1 1 2 3 4

It should print saying \

Answer 1

Integer[] ints = {1, 1, 2, 3, 4};

System.out.println(new HashSet(Arrays.asList(ints)));

Output: [1, 2, 3, 4]