list 的排序 分组 筛选 list操作 list操作技巧

public static void listScreen(){
        List<Person> list = new ArrayList<>();
        list.add(new Person("20","1","a"));
        list.add(new Person("21","2","a"));
        list.add(new Person("20","6","b"));
        list.add(new Person("20","3","a"));
        list.add(new Person("23","5","b"));
        list.add(new Person("20","4","a"));
        System.out.println(list);
        List<String> ter = new ArrayList<>();
        ter.add("20");
        System.out.println("--------筛选--------");
        list = list.stream().filter(person ->ter.contains(person.getAge())).collect(Collectors.toList());
        System.out.println(list);
        System.out.println("--------倒序--------");
        list.sort(Comparator.comparing(Person::getName).reversed());
        System.out.println(list);
        System.out.println("-------正序---------");
        list.sort(Comparator.comparing(Person::getName));
        System.out.println(list);
        System.out.println("-------分组---------");
        Map<String, List<Person>> collect = list.stream().collect(Collectors.groupingBy(Person::getSex));
        System.out.println(collect);
    }