Java8 Stream 创建流

Stream<Integer> stream = new HashSet<Integer>()
                .stream();
Stream<String> stringStream = new ArrayList<String>()
                .stream();

IntStream intStream = IntStream.rangeClosed(1, 100);

Stream<Integer> integerStream = Stream.of(1, 2, 3);
Stream<String> stringStream = Stream.of("喜欢", "天文", "的", "pony", "站长");
AppleStream apple = new AppleStream();
Stream<AppleStream> appleStream = Stream.of(apple, apple, apple);

//重载了支持特定的基本类型流
IntStream intStream = Arrays.stream(new int[]{1, 2, 3});
LongStream longStream = Arrays.stream(new long[]{1L, 2L, 3L});
DoubleStream doubleStream = Arrays.stream(new double[]{1D, 2D, 3D});
        
Stream<String> stringStream = Arrays.stream(new String[]{"喜欢", "天文", "的", "pony", "站长"});
AppleStream apple = new AppleStream();
Stream<AppleStream> appleStream = Arrays.stream(new AppleStream[]{apple, apple, apple});

Stream<String> linesStream = Files.lines(Paths.get("fileStream.txt"));
linesStream.forEach(System.out::println);

// 给定一个初始值seed，和一个`接收一个入参，并带有返回值的函数`
Stream.iterate(10, x -> x + 5)
        .limit(10)
        .forEach(System.out::println);

10
15
20
25
30
35
40
45
50
55

Random random = new Random();
// 接收一个 `无入参，有返回值` 的函数
Stream.generate(() -> random.nextInt(100))
        .limit(10)
        .forEach(System.out::println);

60
56
6
61
7
30
97
64
26
54