//利用Stream.of方法创建流

        Stream<String> stream = Stream.of("hello", "world", "Java8");

        stream.forEach(System.out::println);

        System.out.println("##################");

        //利用Stream.iterate方法创建流

//长度为5的集合 10 11 12 13 14

        Stream.iterate(10, n -> n + 1)

                .limit(5)

                .collect(Collectors.toList())

                .forEach(System.out::println);

        System.out.println("##################");//10 11 12 13 14

        //利用Stream.generate方法创建流

//长度为个随机数

        Stream.generate(Math::random).limit(5).forEach(System.out::println);

        System.out.println("##################");

        //从现有的集合中创建流

        List<String> strings = Arrays.asList("hello", "world", "Java8");

        String string = strings.stream().collect(Collectors.joining(","));

        System.out.println(string);