如何从嵌套的 json volley/android 中检索数据

Question

I want to get all titles from this JSON. I am using the Volley library.

JSON source: https://sheets.googleapis.com/v4/spreadsheets/1AtYF5g2_A3AiAhejVj595bDLxO1zoGq7PNGjbdV9U8Q?fields=sheets.properties.title&key=AIzaSyDLeY5OUn8KKHeBY6PSZJbBE8rIIME_9dc

My Code:

public void getAllName(){
    String urls = "https://sheets.googleapis.com/v4/spreadsheets/1AtYF5g2_A3AiAhejVj595bDLxO1zoGq7PNGjbdV9U8Q?fields=sheets.properties.title&key=AIzaSyDLeY5OUn8KKHeBY6PSZJbBE8rIIME_9dc";

    RequestQueue queue = Volley.newRequestQueue(MainActivity.this);
    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.GET, urls,
            null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                JSONObject feedObj = response.getJSONObject("sheets");
                JSONArray entryArray = feedObj.getJSONArray("properties");

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
        }
    });
    queue.add(jsonObjectRequest);
}

Please tell me how to get all the titles... TIA

Answer 1

You can do the following:

JSONArray jsonArray = jsonObject.getJSONArray("sheets");

List<String> titles = IntStream.range(0,jsonArray.length())
        .mapToObj(i -> jsonArray.getJSONObject(i)
                .getJSONObject("properties")
                .getString("title"))
        .collect(Collectors.toList());

Output:

[CSE522, EEE, BBA, MBA, SWE555, CSE625, CSE721, CSE250, CSE775, CSE499]

Answer 2

Ref: https://stackoverflow.com/a/49839058/13533028

From your Json Response, your title data is inside properties which are inside sheets. JsonObject can be retrieved from Json using getJsonObject("name of the property")

    JSONObject jsonObject = new JSONObject(response);
    JSONObject dataArray = jsonObject.getJSONArray("sheets");

    JSONArray  properties= dataArray.getJsonObject(YOUR_ELEMENT_NO);

now you can use properties.title in the same way and use it as you like.

Also, I would suggest using Retrofit for networking tasks since it makes networking tasks much easier.