java8 Stream流

下面是一些简单的方法的样例：

    @GetMapping("/test")
    public static void test() {
    List<String> list = new ArrayList<String>();
    list.add("3");
    list.add("2");
    list.add("1");
    list.add("5");
    list.add("4");
    list.add("z");
    
    for (String e : list) System.err.println(e);
    
    // Stream 取最小值
    Stream<String> stream = list.stream();
    Optional<String> min = stream.min(String::compareTo);
    if (min.isPresent()) System.out.println(min.get());

    // Stream 取最大值
    Optional<String> max =  list.stream().max(String::compareTo);
    if (max.isPresent()) System.out.println(max.get());

    // Stream 取最大值
    list.stream().max(String::compareTo).ifPresent(System.out::println);
    
    // 存有序List
    List<String> newList = new ArrayList<>();
    
    // Stream 取有序List
    Stream<String> sorted = list.stream().sorted();
    sorted.forEach(elem -> newList.add(elem));
    System.out.println(newList);
    
    list.stream().sorted().forEach(elem -> System.out.println(elem));
    
    // 过滤器
    list.stream().filter(elem -> elem.equals("5") || elem.equals("z")).forEach(elem -> System.err.println("过滤1：" + elem));

    }