How to get JSON data from url?

Question

This is my code to get JSON data in textview .JSON data is inside my code only. Now if my data is in some URL, then how can I get those data?
The old answers uses defaultHTTPClient which is no more supported and I tried using retrofit and volley but not able to understand.

public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    TextView output = (TextView) findViewById(R.id.textView1);

    String strJson="{ \"Employee\" :[{\"id\":\"101\",\"name\":\"Sonoo Jaiswal\",\"salary\":\"50000\"},{\"id\":\"102\",\"name\":\"Vimal Jaiswal\",\"salary\":\"60000\"}] }";

    String data = "";
    try {
        // Create the root JSONObject from the JSON string.
        JSONObject  jsonRootObject = new JSONObject(strJson);

        //Get the instance of JSONArray that contains JSONObjects
        JSONArray jsonArray = jsonRootObject.optJSONArray("Employee");

        //Iterate the jsonArray and print the info of JSONObjects
        for(int i=0; i < jsonArray.length(); i++){
            JSONObject jsonObject = jsonArray.getJSONObject(i);

            int id = Integer.parseInt(jsonObject.optString("id").toString());
            String name = jsonObject.optString("name").toString();
            float salary = Float.parseFloat(jsonObject.optString("salary").toString());

            data += "Node"+i+" : \n id= "+ id +" \n Name= "+ name +" \n Salary= "+ salary +" \n ";
        }
        output.setText(data);
    } catch (JSONException e) {e.printStackTrace();}
}

You can refer http://www.androidhive.info/2012/01/android-json-parsing-tutorial/ — Hiren Patel, Feb 24 '16 at 09:53
I just want to get data from this url http://www.zippytrailers.com/funlearn/topicsMap and show them in textview. — Shwetabh Singh, Feb 24 '16 at 09:55
Possible duplicate of [How to parse JSON in Android](http://stackoverflow.com/questions/9605913/how-to-parse-json-in-android) — Iamat8, Feb 24 '16 at 09:58
You can follow How to parse JSON data in android applications from url tutorial https://www.youtube.com/watch?v=ku9yOcojFT4 — Naresh Narsing, Feb 24 '16 at 10:13
@Yazan if the question isn't worth your time, then leave it alone. Linking to the Jordanian Google page isn't useful. Either find said duplicate or provide an answer using the code in the question — OneCricketeer, Feb 24 '16 at 10:39

score 1 · Accepted Answer · edited May 23 '17 at 11:53

EDIT

Use Volley if httpclient you can't find.

Moreover parsing script is same which mentioned below.

I already written a Blog. Refer that. Hope it helps. Let me clone my blog to match your requirement. Please use proper naming for that. Here is parsing output.

 public class GridUI extends Activity {
 ArrayList<Persons> personsList;
 GridView gridView;
 GridAdapter gridAdapter;
private static final String   url="http://www.zippytrailers.com/funlearn/topicsMap";
   @Override
   protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gridview);
    personsList= new ArrayList<Persons>();
 new JSONAsyncTask().execute(url);
 gridView=(GridView)findViewById(R.id.gridview);
 gridAdapter = new GridAdapter(this, R.layout.gridview_row, personsList);
 gridView.setAdapter(gridAdapter);

 }
 class JSONAsyncTask extends AsyncTask<String, Void, Boolean> {
 ProgressDialog dialog;
 @Override
  protected void onPreExecute() {
  // TODO Auto-generated method stub
  super.onPreExecute();
  dialog=new ProgressDialog(GridUI.this);
  dialog.setMessage("Loading, please wait");
  dialog.setTitle("Connecting server");
  dialog.show();
  dialog.setCancelable(false);

  }


   @Override
  protected Boolean doInBackground(String... urls) {
      try {

//------------------>>
HttpGet httppost = new HttpGet(urls[0]);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(httppost);

// StatusLine stat = response.getStatusLine();
int status = response.getStatusLine().getStatusCode();

 if(status==200){
 HttpEntity entity = response.getEntity();
 String data = EntityUtils.toString(entity);
  JSONObject jsono=new JSONObject(data);
  JSONArray jarray = jsono.getJSONArray("results");
  for (int i = 0; i < jarray.length(); i++) {
   JSONObject object = jarray.getJSONObject(i);

   Persons name = new Persons();

   name.setName(object.getString("syllabus"));
   name.setDescription(object.getString("grade"));
   name.setDob(object.getString("subject"));
   name.setCountry(object.getString("topic"));
   name.setHeight(object.getString("id"));

   personsList.add(name);
  }
  return true;
 }

} catch (ParseException e1) {
 e1.printStackTrace();
} catch (IOException e) {
 e.printStackTrace();
} catch (JSONException e) {
 e.printStackTrace();
}
return false;

}

   @Override
  protected void onPostExecute(Boolean result) {
  super.onPostExecute(result);
  dialog.cancel();
  gridAdapter.notifyDataSetChanged();
  if(result == false)
Toast.makeText(getApplicationContext(), "Unable to fetch data from   server", Toast.LENGTH_LONG).show();
 }

}

Hi Shadow thanks but I am using api 23 and this httpclient is not there. — Shwetabh Singh, Feb 24 '16 at 10:30
and moreover refer this too.http://www.androidhive.info/2014/09/android-json-parsing-using-volley/ parsing from response is same as I mentioned in that.. Happy coding.. — Shadow, Feb 24 '16 at 10:45

score 1 · Answer 2 · edited Feb 25 '16 at 23:10

1

{  
   "Employee":[  
      {  
         "id":"101",
         "name":"Sonoo Jaiswal",
         "salary":"50000"
      },
      {  
         "id":"102",
         "name":"Vimal Jaiswal",
         "salary":"60000"
      }
   ]
}

Remove "\" from your string data like above.then try to parse.your json is not valid one.

check it on https://jsonformatter.curiousconcept.com/

edited Feb 25 '16 at 23:10

OneCricketeer

179,855
19
132
245

answered Feb 24 '16 at 10:23

Uttam Kumar Nayak

31
7

OP is asking to how to parse from api of url link and not from local. – Shadow Feb 24 '16 at 10:24

score 0 · Answer 3 · edited Feb 25 '16 at 23:12

Like this:

String myURL = "https://www.myurl.com/file.json";
String jsonResponse = null;
try {
    jsonResponse = (String) new RetrieveJSONTask(myURL).execute().get();
} catch (ExecutionException | InterruptedException e) {
    // Do something
}

If you need to get an object you can do:

JSONObject jsonObject = null;
try {
    jsonObject = new JSONObject(jsonResponse);

    // Here you get an specific tag named "title" from the first object of an array named "itens"
    String title = jsonObject.getJSONArray("items").getJSONObject(0).getString("title");

} catch(JSONException e) {
     // Do something
}

score 0 · Answer 4 · edited Feb 25 '16 at 23:11

Try this code:

try {
    URL url = new URL("http://www.zippytrailers.com/funlearn/topicsMap");
    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

    InputStream in = new BufferedInputStream(urlConnection.getInputStream());
    BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"), 8);
    StringBuilder sb = new StringBuilder();

    String line = null;
    while ((line = reader.readLine()) != null)
    {
        sb.append(line + "\n");
    }
    String result = sb.toString();
    System.out.println("result"+result);
} catch (Exception e){
    System.out.println(" error"+e);
}

How to get JSON data from url?

4 Answers4