Java8 stream – HashSet of bytes from intstream

I'm trying to create a HashSet < byte > bytes 1, 2, 3,... 9 using the Java 8 streams API I want to use intstream and demote the value to byte

I'm trying a variant

HashSet < bytes > num = intstream range(1,10). collect(Collectors.toSet());

HashSet < bytes > num = intstream range(1,10). map(e – >((byte)e)). collect(Collectors.toSet());

But none of this worked

Error:(34,73) java: method collect in interface java.util.stream.IntStream cannot be applied to given types;
  required: java.util.function.supplier<R>,java.util.function.ObjIntConsumer<R>,java.util.function.BiConsumer<R,R>
  found: java.util.stream.Collector<java.lang.Object,capture#1 of ?,java.util.Set<java.lang.Object>>
  reason: cannot infer type-variable(s) R
    (actual and formal argument lists differ in length)

Do I need to do flatmap or maptoobject?

Solution

You need to use maptoobj because HashSet and all generics require objects

Set<Byte> nums = IntStream.range(1,10)
    .mapToObj(e -> (byte) e)
    .collect(Collectors.toSet());