java8新特性（Stream API）

//1. 创建 Stream
    @Test
    public void test1(){
        //1. Collection 提供了两个方法  stream() 与 parallelStream()
        List<String> list = new ArrayList<>();
        Stream<String> stream = list.stream(); //获取一个顺序流
        Stream<String> parallelStream = list.parallelStream(); //获取一个并行流
        
        //2. 通过 Arrays 中的 stream() 获取一个数组流
        Integer[] nums = new Integer[10];
        Stream<Integer> stream1 = Arrays.stream(nums);
        
        //3. 通过 Stream 类中静态方法 of()
        Stream<Integer> stream2 = Stream.of(1,2,3,4,5,6);
        
        //4. 创建无限流
        //迭代
        Stream<Integer> stream3 = Stream.iterate(0, (x) -> x + 2).limit(10);
        stream3.forEach(System.out::println);
        
        //生成
        Stream<Double> stream4 = Stream.generate(Math::random).limit(2);
        stream4.forEach(System.out::println);
        
    }