public class Test08 {
    public static void main(String[] args) throws ParseException {
        ArrayList<Date> list = new ArrayList<>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i <3 ; i++) {
            System.out.println("请输入第"+(i+1)+"个日期 格式yyyy-MM-dd：");
            String time = sc.nextLine();
            Date date = sdf.parse(time);
            list.add(date);
        }
        System.out.println("排序前的日期");
        for (Date date : list) {
            System.out.println(sdf.format(date));
        }
        Collections.sort(list);
        System.out.println("排序后的日期");
        for (Date date : list) {
            System.out.println(sdf.format(date));
        }
    }
}