Is there a way that I can return arrays without String[] params?

Question

 public class PerformNetworkTasks extends AsyncTask<String, String, String> {

        @Override
        protected String doInBackground(String... params) {
            HttpURLConnection connection = null;
            BufferedReader reader = null;

            try {
                URL url = new URL(params[0]); 
                connection = (HttpURLConnection) url.openConnection();
                connection.connect(); //getting the connection to the URL to read JSON data
                InputStream stream = connection.getInputStream();
                reader = new BufferedReader(new InputStreamReader(stream));

                StringBuffer buffer = new StringBuffer();

                String line = "";
                while ((line = reader.readLine()) != null) {
                    buffer.append(line);
                }

                String jsonText = buffer.toString(); // gets what the URL returns as JSON



                JSONObject obj = new JSONObject(jsonText); // using JSONObject to pass to a JSONArray to search for the JSON

                List<String> allInfo = new ArrayList<String>(); // list to put all the returned information

                JSONArray linemanques = obj.getJSONArray("linemanques"); //selects the array to read from
                for (int i = 0; i < linemanques.length(); i++) {

                        JSONObject questionParts = linemanques.getJSONObject(i);
                        quesnum = questionParts.getString("quesnum"); // all of questionParts.getString() are for getting the data in the JSONArray
                        questype = questionParts.getString("questype");
                        question = questionParts.getString("question");
                        ans1 = questionParts.getString("ans1");
                        ans2 = questionParts.getString("ans2");
                        ans3 = questionParts.getString("ans3");
                        ans4 = questionParts.getString("ans4");
                        correctans = questionParts.getString("correctans");
                        category = questionParts.getString("category");
                        notes = questionParts.getString("notes");
                        flag = questionParts.getString("flag");


                    allInfo.add(quesnum);    
                    allInfo.add(questype);
                    allInfo.add(question);
                    allInfo.add(ans1);
                    allInfo.add(ans2);
                    allInfo.add(ans3);
                    allInfo.add(ans4);
                    allInfo.add(correctans);
                    allInfo.add(category);
                    allInfo.add(notes);
                    allInfo.add(flag);
                    allInfo.add("\n");
                }

                 return allInfo.toString(); 
                 /* 
                  right now I am returning the list as a String, 
                  so that I can actually view the data. 
                  I need to put this data into their own TextViews. 
                  So how can I return the list I have so that I can set
                  the individual TextViews as one section from the list?  
                  */     

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (JSONException e) {
                e.printStackTrace();
            } finally {
            }
            if (connection != null) {
                connection.disconnect();
            }
            try {
                if (reader != null) {
                    reader.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;

        }


        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            inputDataTV.setText(result);
        }

I need to return some data individually. So I need to return an array (i think) so that I can set the TextView as e.g. arrays.get(number).

Is there some other way that I am not realizing here, or should I continue with what I am doing to get the data individually?

Just to add, I am getting the info from a website.

Can you change the code? You could just change the method signature to return List<String> and then return allInfo instead of return allInfo.toString() - is that what you are after? — blurfus
– blurfus, Commented Jan 9, 2020 at 2:05
Btw, the incoming String... params only uses the first one (in position 0 of the array) - you could change this to simply String urlString and then craft your URL like URL url = new URL(urlString); — blurfus
– blurfus, Commented Jan 9, 2020 at 2:08

Md. Enamul Haque · Accepted Answer · 2020-01-09 02:32:50Z

You can return any data type you want but your AsyncTask structure should be based on result data type

  public class PerformNetworkTasks extends AsyncTask<String, String, List<String>/*resultParam*/> {

    @Override
    protected List<String>/*will same as result parma*/ doInBackground(String... params) {
        return null;/*now you can return list of string*/
    }

    @Override
    protected void onPostExecute(List<String>/*finally receive result*/ result) {
        super.onPostExecute(result);
    }
}

so your code will be

 public class PerformNetworkTasks extends AsyncTask<String, String, List<String>> {

    @Override
    protected List<String> doInBackground(String... params) {
        HttpURLConnection connection = null;
        BufferedReader reader = null;

        try {
            URL url = new URL(params[0]);
            connection = (HttpURLConnection) url.openConnection();
            connection.connect(); //getting the connection to the URL to read JSON data
            InputStream stream = connection.getInputStream();
            reader = new BufferedReader(new InputStreamReader(stream));

            StringBuffer buffer = new StringBuffer();

            String line = "";
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }

            String jsonText = buffer.toString(); // gets what the URL returns as JSON


            JSONObject obj = new JSONObject(jsonText); // using JSONObject to pass to a JSONArray to search for the JSON

            List<String> allInfo = new ArrayList<>(); // list to put all the returned information

            JSONArray linemanques = obj.getJSONArray("linemanques"); //selects the array to read from
            for (int i = 0; i < linemanques.length(); i++) {

                JSONObject questionParts = linemanques.getJSONObject(i);
                quesnum = questionParts.getString("quesnum"); // all of questionParts.getString() are for getting the data in the JSONArray
                questype = questionParts.getString("questype");
                question = questionParts.getString("question");
                ans1 = questionParts.getString("ans1");
                ans2 = questionParts.getString("ans2");
                ans3 = questionParts.getString("ans3");
                ans4 = questionParts.getString("ans4");
                correctans = questionParts.getString("correctans");
                category = questionParts.getString("category");
                notes = questionParts.getString("notes");
                flag = questionParts.getString("flag");


                allInfo.add(quesnum);
                allInfo.add(questype);
                allInfo.add(question);
                allInfo.add(ans1);
                allInfo.add(ans2);
                allInfo.add(ans3);
                allInfo.add(ans4);
                allInfo.add(correctans);
                allInfo.add(category);
                allInfo.add(notes);
                allInfo.add(flag);
                allInfo.add("\n");
            }

            return allInfo;
             /*
              right now
              I am returning the list as a String,
              so that I can actually view the data.
              I need to put this data into their own TextViews.
              So how can I return the list I have so that I can set
              the individual TextViews as one section from the list?
              */

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            e.printStackTrace();
        } finally {
        }
        if (connection != null) {
            connection.disconnect();
        }
        try {
            if (reader != null) {
                reader.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }


    @Override
    protected void onPostExecute(List<String> result) {
        super.onPostExecute(result);
        inputDataTV.setText(result.get(0));
    }
}

Thank you, I had tried this but had edited the wrong spot in the PerformNetworkTasks method signature. I went to watch a youtube video and figured out that it is formed <params, progress, result>. Thank you.

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