Java tutorial
import java.util.Collection; import java.util.TreeSet; import java.util.stream.Collectors; import java.util.stream.Stream; public class Main { public static void main(String[] args) { Stream<String> s = Stream.of("a", "b", "c"); Collection<String> names = s.collect(Collectors.toCollection(TreeSet::new)); System.out.println(names); } }