list集合中的map集合通过map的creattime键值进行时间排序,map不止有creattime键值

，也可以根据其他键值进行排序，以下是根据creattime进行排序的示例代码：

import java.util.*;

public class Main {
    public static void main(String[] args) {
        List<Map<String, Object>> list = new ArrayList<>();
        Map<String, Object> map1 = new HashMap<>();
        map1.put("name", "Alice");
        map1.put("age", 20);
        map1.put("creattime", new Date(2021, 0, 1));
        list.add(map1);

        Map<String, Object> map2 = new HashMap<>();
        map2.put("name", "Bob");
        map2.put("age", 25);
        map2.put("creattime", new Date(2021, 3, 1));
        list.add(map2);

        Map<String, Object> map3 = new HashMap<>();
        map3.put("name", "Charlie");
        map3.put("age", 30);
        map3.put("creattime", new Date(2021, 2, 1));
        list.add(map3);

        // 按照creattime排序
        Collections.sort(list, new Comparator<Map<String, Object>>() {
            @Override
            public int compare(Map<String, Object> o1, Map<String, Object> o2) {
                Date d1 = (Date) o1.get("creattime");
                Date d2 = (Date) o2.get("creattime");
                return d1.compareTo(d2);
            }
        });

        // 输出排序结果
        for (Map<String, Object> map : list) {
            System.out.println(map);
        }
    }
}

输出结果：

{name=Alice, age=20, creattime=Sat Jan 01 00:00:00 CST 3921}
{name=Charlie, age=30, creattime=Mon Mar 01 00:00:00 CST 3921}
{name=Bob, age=25, creattime=Mon Apr 01 00:00:00 CST 3921}