package basic; import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; //interface StreamBBFoo { // int m(int n); //} public class StreamBB2 { public static void main(String[] args) { System.out.println("This is Java8"); } public static int run() { StreamBBFoo foo = (n) -> n + 1; List<Integer> integers = Arrays.asList(1, 2, 3, 4); List<Integer> mapped = integers.stream().map(foo::m).collect(Collectors.toList()); return mapped.size(); } }