generics - Java int[] array to HashSet<Integer>

Question

I have an array of int:

int[] a = {1, 2, 3};

I need a typed set from it:

Set<Integer> s;

If I do the following:

s = new HashSet(Arrays.asList(a));

it, of course, thinks I mean:

List<int[]>

whereas I meant:

List<Integer>

This is because int is a primitive. If I had used String, all would work:

Set<String> s = new HashSet<String>(
    Arrays.asList(new String[] { "1", "2", "3" }));

How to easily, correctly and succinctly go from:

A) int[] a...

to

B) Integer[] a ...

Thanks!

question from:https://stackoverflow.com/questions/12030661/java-int-array-to-hashsetinteger

Answer 1

Using Stream:

// int[] nums = {1,2,3,4,5}
Set<Integer> set = Arrays.stream(nums).boxed().collect(Collectors.toSet())