I am trying to work on volley with gridview. JsonObjectRequest does not fetch any response. I looked up for links on stackoverflow abt JsonObjectRequest passing null as parameter and changing volley version but nothing works as the error was Volley - Cannot Resolve Constructor "JSONObjectRequest. Now no error but no response also. Any help appreciated! Below example link : http://hemanthsomaraju.blogspot.com/2019/03/android-grid-view-using-volley-api.html and volley version: implementation 'com.mcxiaoke.volley:library:1.0.19'. Links referred: Volley - Cannot Resolve Constructor "JSONObjectRequest

public class OutputActivity extends AppCompatActivity {
GridView ListView;
VolleyListViewAdapter adapter;
private List<CommonBean> VolleyList = new ArrayList<CommonBean>();
private ProgressDialog mprocessingdialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_output);
    ListView = (GridView) findViewById(R.id.ListView);
    adapter = new VolleyListViewAdapter(OutputActivity.this, VolleyList);
    ListView.setAdapter(adapter);
    new OutputActivity.GetListAsync().execute();
}
private class GetListAsync extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        mprocessingdialog = new ProgressDialog(OutputActivity.this);
        mprocessingdialog.setTitle("Please Wait..");
        mprocessingdialog.setMessage("Loading");
        mprocessingdialog.setIndeterminate(false);
        mprocessingdialog.setCancelable(false);
        mprocessingdialog.show();
    }
    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub
        JSONObject jsonObject = null;
        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.GET,
                "https://api.fnpplus.com/productapi/api/rest/v1.2/productList?catalogId=india",
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d("rlog", response.toString());
                        try {
                            JSONObject jsonObj = new JSONObject(response.toString());
                            JSONObject jsonObject = jsonObj.getJSONObject("data");
                            JSONArray jsonArray = jsonObject.getJSONArray("productResults");
                            Log.d("rlog", jsonArray.toString());
                            for (int i = 0; i < jsonArray.length(); i  ) {
                                JSONObject obj = jsonArray.getJSONObject(i);
                                CommonBean commonBean = new CommonBean();
                                commonBean.setTextView1(obj.optString("productName"));
                                JSONObject jsonObject2 = obj.getJSONObject("price");
                                Log.d("rlog1", jsonObject2.toString());
                                commonBean.setTextView2(jsonObject2.optString("price"));
                                Log.d("rlog12", jsonObject2.optString("price"));
                                JSONObject jsonObject1 = obj.getJSONObject("productImage");
                                Log.d("rlog1", jsonObject1.toString());
                                commonBean.setImageView(jsonObject1.optString("path"));
                                Log.d("rlog12", jsonObject1.optString("path"));
                                VolleyList.add(commonBean);
                            }
                            mprocessingdialog.dismiss();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                        adapter.notifyDataSetChanged();
                    }
                }, new Response.ErrorListener() {
            @Override
            public void one rrorResponse(VolleyError error) {
                VolleyLog.d("rlog", "Error: "   error.getMessage());
            }
        });
        jsonObjReq.setRetryPolicy(new DefaultRetryPolicy(0, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
        RequestQueue requestQueue = Volley.newRequestQueue(OutputActivity.this);
        requestQueue.add(jsonObjReq);
        return null;
    }
    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        new Timer().schedule(new TimerTask() {
            @Override
            public void run() {
                mprocessingdialog.dismiss();
            }
        }, 30000);
    }
}

}

CodePudding user response：

Go with the StringRequest and add your data as per your expected conditions

No Need to use AsyncTask and you can add loader in code also.

 RequestQueue queue;
        String URL = "https://api.fnpplus.com/productapi/api/rest/v1.2/productList?catalogId=india";
        queue = Volley.newRequestQueue(this);
        StringRequest request = new StringRequest(Request.Method.GET, URL, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    JSONObject jsonObject = new JSONObject(response);
                    JSONObject dataJsonObject = jsonObject.getJSONObject("data");
                    JSONArray jsonArray = dataJsonObject.getJSONArray("productResults");
                    Log.d("rlog", jsonArray.toString());
                 } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void one rrorResponse(VolleyError error) {
                Log.d("error", error.toString());
            }
        });
        request.setRetryPolicy(new DefaultRetryPolicy(5000,
                DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
                DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

        queue.add(request);
}