package lambdasinaction.chap4; import java.util.*; import java.util.stream.*; import static java.util.stream.Collectors.toList; public class StreamVsCollection { public static void main(String...args){ List<String> names = Arrays.asList("Java8", "Lambdas", "In", "Action"); Stream<String> s = names.stream(); s.forEach(System.out::println); // uncommenting this line will result in an IllegalStateException // because streams can be consumed only once //s.forEach(System.out::println); } }