JSONparser from Androidhive Tutorial, Nosuchmethoderror in Defaulthttpclient

Download JSON in an AsyncTask

You need to actually do a network operation in order to download the JSON response. Then, you need to parse it correctly.

Here is code that would download the JSON response and parse it, you need to iterate over each JSONObject in the JSONArray:

//@Override
protected List<DublinBusObject> doInBackground(String... params) {
    String liveUpdateUrl = params[0];
    List<DublinBusObject> dublinBusObjects = new ArrayList<>();
    try {

        //Use JSONParser to download the JSON
        JSONParser jsonParser = new JSONParser();
        JSONObject jsonObject = jsonParser.makeHttpRequest(
                liveUpdateUrl, "GET", new HashMap<String, String>());

        JSONArray jsonArray= jsonObject.getJSONArray("stops");
        for (int x = 0; x < jsonArray.length(); x++) {

            JSONObject jsonItem = jsonArray.getJSONObject(x);

            this.busRoute = jsonItem.getString("bus_num");
            this.busDescription = jsonItem.getString("description");
            this.bueTime = jsonItem.getString("exected_dep");
            this.busStopId = jsonItem.getString("stop_id");

            DublinBusObject dublinBusObject = new DublinBusObject(busRoute, busDescription, bueTime, busStopId);
            dublinBusObjects.add(dublinBusObject);
        }

    } catch (JSONException e) {
        e.printStackTrace();
    }
    return dublinBusObjects;
}

This uses this JSONParser class from another answer of mine:

import android.util.Log;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;

public class JSONParser {

    String charset = "UTF-8";
    HttpURLConnection conn;
    DataOutputStream wr;
    StringBuilder result;
    URL urlObj;
    JSONObject jObj = null;
    StringBuilder sbParams;
    String paramsString;

    public JSONObject makeHttpRequest(String url, String method,
                                      HashMap<String, String> params) {

        sbParams = new StringBuilder();
        int i = 0;
        for (String key : params.keySet()) {
            try {
                if (i != 0){
                    sbParams.append("&");
                }
                sbParams.append(key).append("=")
                        .append(URLEncoder.encode(params.get(key), charset));

            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            i++;
        }

        if (method.equals("POST")) {
            // request method is POST
            try {
                urlObj = new URL(url);

                conn = (HttpURLConnection) urlObj.openConnection();

                conn.setDoOutput(true);

                conn.setRequestMethod("POST");

                conn.setRequestProperty("Accept-Charset", charset);

                conn.setReadTimeout(10000);
                conn.setConnectTimeout(15000);

                conn.connect();

                paramsString = sbParams.toString();

                wr = new DataOutputStream(conn.getOutputStream());
                wr.writeBytes(paramsString);
                wr.flush();
                wr.close();

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        else if(method.equals("GET")){
            // request method is GET

            if (sbParams.length() != 0) {
                url += "?" + sbParams.toString();
            }

            try {
                urlObj = new URL(url);

                conn = (HttpURLConnection) urlObj.openConnection();

                conn.setDoOutput(false);

                conn.setRequestMethod("GET");

                conn.setRequestProperty("Accept-Charset", charset);

                conn.setConnectTimeout(15000);

                conn.connect();

            } catch (IOException e) {
                e.printStackTrace();
            }

        }

        try {
            //Receive the response from the server
            InputStream in = new BufferedInputStream(conn.getInputStream());
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            result = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }

            Log.d("JSON Parser", "result: " + result.toString());

        } catch (IOException e) {
            e.printStackTrace();
        }

        conn.disconnect();

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(result.toString());
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON Object
        return jObj;
    }
}

why is AsyncTask doing deprecated lines ? in my code?

HttpGet, HttpClient ,HttpResponse and HttpEntity are depreceated.

Now you have to use HttpUrlConnection

URL url = new URL("http://www.android.com/");
   HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
   try {
     InputStream in = new BufferedInputStream(urlConnection.getInputStream());
     readStream(in);
    finally {
     urlConnection.disconnect();
   }
 }

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