降序数组列表<hashmap>

Question

如何在Arraylist上降序排序<hashmap<字符串，字符串>？我不知道怎么做

我的代码ArrayList<哈希映射<字符串，字符串>gt；data=new ArrayList<哈希映射<字符串，字符串>gt；((；

for (int i = 0; i < list_data.size(); i++) {
NSM = list_data.get(i).get("nama_sekolah");
HashMap<String,String> unsortMap = new HashMap<>();
HashMap<String, String> maps = new HashMap<String, String>();
Nuang.set(i, minUang / Double.parseDouble(String.valueOf(Nuang.get(i))));
NJsiswa.set(i, Double.parseDouble(String.valueOf(NJsiswa.get(i))) / maxSiswa);
NEks.set(i, Double.parseDouble(String.valueOf(NEks.get(i))) / maxEks);
NAk.set(i, Double.parseDouble(String.valueOf(NAk.get(i))) / maxAk);
NLes.set(i, Double.parseDouble(String.valueOf(NLes.get(i))) / maxLes);
NBs.set(i, Double.parseDouble(String.valueOf(NBs.get(i))) / maxBs);
Double NNuang = Double.parseDouble(String.valueOf(Nuang.get(i)));
Double NNJsiswa = Double.parseDouble(String.valueOf(NJsiswa.get(i)));
Double NNEks = Double.parseDouble(String.valueOf(NEks.get(i)));
Double NNAk = Double.parseDouble(String.valueOf(NAk.get(i)));
Double NNLes = Double.parseDouble(String.valueOf(NLes.get(i)));
Double NNBs = Double.parseDouble(String.valueOf(NBs.get(i)));
Q1 = 0.5 * ((NNuang * BUs) + (NNJsiswa * BJs) + (NNEks * BEks) + (NNAk * BAk) + (NNLes * BLes) + (NNBs * BBs));
Q2 = 0.5 * ((Math.pow(NNuang, BUs)) * (Math.pow(NNJsiswa, BJs)) * (Math.pow(NNEks, BEks)) * (Math.pow(NNAk, BAk)) * (Math.pow(NNLes, BLes)) * (Math.pow(NNBs, BBs)));
unsortMap.put("nama_sekolah",NSM);
unsortMap.put("nilai",String.valueOf(Q1+Q2));
data.add(unsortMap);
recyclerView.setAdapter(new AdapterList(ViewList.this,data));
}

Answer 1

您可以这样做：

import java.util.*;
public class Details  {
public static void main(String args[]){
ArrayList<String> arraylist = new ArrayList<String>();
arraylist.add("AA");
arraylist.add("ZZ");
arraylist.add("CC");
arraylist.add("FF");
/*Unsorted List: ArrayList content before sorting*/
System.out.println("Before Sorting:");
for(String str: arraylist){
System.out.println(str);
}
/* Sorting in decreasing order*/
Collections.sort(arraylist, Collections.reverseOrder());
/* Sorted List in reverse order*/
System.out.println("ArrayList in descending order:");
for(String str: arraylist){
System.out.println(str);
}
}

}

我在这里找到了这个例子：https://beginnersbook.com/2013/12/sort-arraylist-in-descending-order-in-java/