'How to count json object item?

I'm parsing a JSON string in Android which looks like this:

 [
   {
     "id":70,
     "selection":"25"
    },
    {
      "id":71,
      "selection":"50"
    },
    {
      "id":72,
      "selection":"50"
    }
 ]

Now I want to get the total count of all selection and display it inside a textview. Can anyone give me an example how to do this, or any tutorial about this?

For example:

selection 25 = 1
selection 50 = 2

Thanks for any help!

javaandroidjsonandroid-volleypythonhtmlflask


Solution 1:[1]

I think what you're looking for is something like this:

        JsonArray selections = new JsonArray(); // This is your parsed json object
        HashMap<Integer, Integer> count = new HashMap<>();
        for (JsonElement element : selections) {
            JsonObject jsonObject = element.getAsJsonObject();
            if(jsonObject.has("selection")) {
                int selValue = jsonObject.get("selection").getAsInt();
                if(count.containsKey(selValue)) {
                    count.put(selValue, count.get(selValue) + 1);
                } else {
                    count.put(selValue, 1);
                }
            }
        }

What this will do is loop over your json array and get the value of each selection element. To keep track of the count it increments the count inside of the count hashmap.

You can then get the count for a specific value from the hashmap:

count.get(25); // returns 1
count.get(50); // returns 2
// etc...

Solution 2:[2]

you can get the array of the json and iterate and calculate the sum of the selection

JSONArray selections = jsonObj.getJSONArray("selections");

// looping through All Selections
int totalCount = selections.length();

Solution 3:[3]

If you are using Jackson in Java 8, you can first convert the given JSON string to List<Map<String, Object>>, then transform it into List<Integer> for selection. Finally, you can count occurrences in this list as follows:

ObjectMapper mapper = new ObjectMapper();
List<Map<String, Object>> jsonObj = mapper.readValue(jsonStr, new TypeReference<List<Map<String, Object>>>(){});
Map<Integer, Long> counted = jsonObj.stream()
        .map(x -> Integer.valueOf(x.get("selection").toString()))
        .collect(Collectors.toList())
        .stream()
        .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

System.out.println(counted.toString());

Console output:

{50=2, 25=1}

Solution 4:[4]

    ArrayList<String> data = new ArrayList<>();
    ArrayList<String> datacount = new ArrayList<>();


            jsonStr = "Your JSON"

            JSONArray jsonArr= null;
            try {
                jsonArr = new JSONArray(jsonStr);
                for (int i = 0; i < jsonArr.length(); i++) {
                    JSONObject jsonObj = jsonArr.getJSONObject(i);
                    //here you can set to TextView
                    String selection = jsonObj.getString("selection");
                    //System.out.println("adcac"+selection);

                    if (data.contains(selection)) {

                        int index = data.indexOf(selection);

                        int count = Integer.parseInt(datacount.get(index))+1;

    //                    System.out.println("Index==="+index+"---count---"+count);
                        datacount.set(index,String.valueOf(count));
                    } else {
                        datacount.add(String.valueOf(1));
                        data.add(selection);
                    }
     // Here you can get data and data count...  
    //                System.out.println("data---"+datacount.toString());
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }

Solution 5:[5]

Why doesn't anybody use Json Path to solve this in two lines?

Solution 6:[6]

I assume you want to take an input (e.g. shoe link) from the user and then do some operations based on the input.

To access the HTML form from / path you need to enable both GET and POST requests in that route. Otherwise, when you try to access the root path / from your browser, you will get the HTTP Method not allowed error.

app.py:

from flask import Flask, render_template, request

app = Flask(__name__)


def get_value_related_info(value):
    return f"You have entered {value}"


@app.route('/', methods=['POST', 'GET'])
def getvalue():
    if request.method == "POST":
        HTML_Info = request.form['data_bridge']
        return get_value_related_info(HTML_Info)
    return render_template('form.html', text="")


if __name__ == "__main__":
    app.run(debug=True)

Output:

  • Before form submission:

before form submission

  • After form submission:

after form submission

templates/form.html:

<html>
<head>
    <title>Form example</title>
</head>
<body>
<form name="passdata" action="{{ url_for('getvalue') }}" method="POST">
    <input type='text' name="data_bridge" placeholder="paste shoe link here">
    <input type="submit">
</form>
</body>
</html>

Explanation:

  • I have mocked the functionality on the user input in get_value_related_info method.

References:

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 martijn p
Solution 2
Solution 3 LHCHIN
Solution 4
Solution 5 d00d
Solution 6 arsho

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