使用Double以逆序对hashmap进行排序

import java.util.*;

public class HashMapSort {
    public static void main(String[] args) {
        // 创建一个HashMap
        HashMap<String, Double> hashMap = new HashMap<>();
        hashMap.put("A", 3.5);
        hashMap.put("B", 2.8);
        hashMap.put("C", 4.2);
        hashMap.put("D", 1.9);

        // 将HashMap转换为List
        List<Map.Entry<String, Double>> list = new ArrayList<>(hashMap.entrySet());

        // 使用Comparator对List进行排序
        Collections.sort(list, new Comparator<Map.Entry<String, Double>>() {
            @Override
            public int compare(Map.Entry<String, Double> o1, Map.Entry<String, Double> o2) {
                // 降序排序
                return o2.getValue().compareTo(o1.getValue());
            }
        });

        // 打印排序结果
        for (Map.Entry<String, Double> entry : list) {
            System.out.println(entry.getKey() + ": " + entry.getValue());
        }
    }
}