根据特定值对 ArrayList<DayOfWeek> 进行排序

Question

我有一个ArrayList<DayOfWeek>让我们说["MONDAY","WEDNESDAY","FRIDAY"]

我的目标是以DayOfTheWeek循环方式基于 a 对其进行排序。

输入： "WEDNESDAY"

排序列表： ["WEDNESDAY","FRIDAY","MONDAY"]

该列表保证从周一到周日排序。不能保证输入日期在列表中，在这种情况下，排序从列表中的下一个值开始。

Answer 1

我建议使用类似于此的方法：

如何在java中将数组值排序为循环格式？

每个DayOfWeek都有自己的 ID 编号，对应于其在排序中的预期位置，因此您可以围绕这些编号旋转。

Answer 2

Collections#rotate

演示：

import java.time.DayOfWeek;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<DayOfWeek> list = new ArrayList<>(List.of(DayOfWeek.MONDAY, DayOfWeek.TUESDAY, DayOfWeek.WEDNESDAY,
                DayOfWeek.THURSDAY, DayOfWeek.FRIDAY, DayOfWeek.SUNDAY));

        Collections.rotate(list, list.size() - list.indexOf(DayOfWeek.WEDNESDAY));

        System.out.println(list);
    }
}

输出：

[WEDNESDAY, THURSDAY, FRIDAY, SUNDAY, MONDAY, TUESDAY]

交互的：

import java.time.DayOfWeek;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        List<DayOfWeek> list = new ArrayList<>(List.of(DayOfWeek.MONDAY, DayOfWeek.TUESDAY, DayOfWeek.WEDNESDAY,
                DayOfWeek.THURSDAY, DayOfWeek.FRIDAY, DayOfWeek.SUNDAY));

        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter the day: ");
        String day = scanner.nextLine();

        try {
            Collections.rotate(list, list.size() - list.indexOf(DayOfWeek.valueOf(day.toUpperCase())));
            System.out.println(list);
        } catch (IllegalArgumentException e) {
            System.out.println("Invalid input");
        }
    }
}

示例运行：

Enter the day: wednesday
[WEDNESDAY, THURSDAY, FRIDAY, SUNDAY, MONDAY, TUESDAY]