reading JSON data from URL

Question

I am trying to parse some JSON data, but my app doesn't do anything because i can't seem to get any response from URL, i tried to open URL connection in few different ways, but it's still the same. for Example :

urlMy=new URL(string);
    URLConnection tc = urlMy.openConnection();
    BufferedReader in = new BufferedReader(new InputStreamReader(
            tc.getInputStream()));
    String line=in.readLine();

doesn't return anything, it even dismisses everything in my function written below that code.

Or

    urlMy=new URL(examp);
InputStream   inputStream = urlMy.openConnection().getInputStream();
InputStreamReader reader = new InputStreamReader(inputStream);
BufferedReader bR = new BufferedReader(reader);

the same thing. This function is called and like it never happend, every function after this one executes, so it's not in the endless loop, but every bit of code in this function after this example code is ignored. if i remove this code for reading url, everthing else works.

Answer 1

Try to use AsyncTask,try something like:

class MyAsyncTask extends AsyncTask<String, String, Void> {

    private ProgressDialog progressDialog = new ProgressDialog(MainActivity.this);
    InputStream inputStream = null;
    String result = ""; 

    protected void onPreExecute() {
        progressDialog.setMessage("Downloading your data...");
        progressDialog.show();
        progressDialog.setOnCancelListener(new OnCancelListener() {
            public void onCancel(DialogInterface arg0) {
                MyAsyncTask.this.cancel(true);
            }
        });
    }

    @Override
    protected Void doInBackground(String... params) {

        String url_select = "http://yoururlhere.com"

                ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();

        try {
            // Set up HTTP post

            // HttpClient is more then less deprecated. Need to change to URLConnection
            HttpClient httpClient = new DefaultHttpClient();

            HttpPost httpPost = new HttpPost(url_select);
            httpPost.setEntity(new UrlEncodedFormEntity(param));
            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();

            // Read content & Log
            inputStream = httpEntity.getContent();
        } catch (UnsupportedEncodingException e1) {
            Log.e("UnsupportedEncodingException", e1.toString());
            e1.printStackTrace();
        } catch (ClientProtocolException e2) {
            Log.e("ClientProtocolException", e2.toString());
            e2.printStackTrace();
        } catch (IllegalStateException e3) {
            Log.e("IllegalStateException", e3.toString());
            e3.printStackTrace();
        } catch (IOException e4) {
            Log.e("IOException", e4.toString());
            e4.printStackTrace();
        }
        // Convert response to string using String Builder
        try {
            BufferedReader bReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"), 8);
            StringBuilder sBuilder = new StringBuilder();

            String line = null;
            while ((line = bReader.readLine()) != null) {
                sBuilder.append(line + "\n");
            }

            inputStream.close();
            result = sBuilder.toString();

        } catch (Exception e) {
            Log.e("StringBuilding & BufferedReader", "Error converting result " + e.toString());
        }
    } // protected Void doInBackground(String... params)


    protected void onPostExecute(Void v) {

        //parse JSON data
        try{
            JSONArray jArray = new JSONArray(result);

            for(i=0; i < jArray.length(); i++) {

                JSONObject jObject = jArray.getJSONObject(i);

                String name = jObject.getString("name");
                String tab1_text = jObject.getString("tab1_text");
                int active = jObject.getInt("active");


            } // End Loop

            this.progressDialog.dismiss();

        } catch (JSONException e) {

            Log.e("JSONException", "Error: " + e.toString());

        } // catch (JSONException e)


    } // protected void onPostExecute(Void v)

} //class MyAsyncTask extends AsyncTask<String, String, Void>

Answer 2

In the last Google I/O, Google released a new library called Volley. It's fast for HTTP requests, very easy to use and you can set it up to return JSONObjects ready for parsing. https://developers.google.com/events/io/sessions/325304728