How to sum json value after sorted in java android?

Question

Following Json needs to group by city to get array along with count if city have same array value. after that I want to sort the 2 biggest and the rest are added together, but how to do it?

{
"data": [
        {
            "ID": 47,
            "city": "Jakarta"
        },
        {
            "ID": 48,
            "city": "Bogor"
        },
        {
           "ID": 49,
            "city": "Bogor"
        },
        {
            "ID": 50,
            "city": "Jakarta"
        },
        {
            "ID": 51,
            "city": "Jakarta"
        },
        {
            "ID": 52,
            "city": "Bali"
        },
        {
            "ID": 50,
            "city": "Lampung"
        }
    ]
}

and i have tried so far is group by city to get array

try {
        JSONObject jsonObject = new JSONObject(result);
        HashMap<String,Integer> hashMap = new HashMap<>();
        for (int i=0;i<jsonObject.getJSONArray("data").length();i++){
            JSONObject innerJsonObject = jsonObject.getJSONArray("data").getJSONObject(i);
            String key = innerJsonObject.getString("city");
            if(hashMap.containsKey(key)){
                int count = hashMap.get(key)+1;
                hashMap.put(key,count);
            }else {
                hashMap.put(key,1);
            }
        }
        Log.e("Hashmap---",hashMap.toString());
    } catch (JSONException e) {
        e.printStackTrace();
    }

and the result is :

• Bogor = 2
• Jakarta = 3
• Bali = 1
• Lampung = 1

the expected result is :

• Jakarta = 3

• Bogor = 2

• Another city = 2

Answer 1

Try to add that HashMap into TreeMap after the for loop like this

     Map<String, Integer> reverseSortedMap = new TreeMap<String, 
        Integer>(Collections.reverseOrder());

      reverseSortedMap.putAll(hashMap);//your hashMap with count of city

      System.out.println("Reverse Sorted Map   : " + reverseSortedMap);