Working with JSON by reference. How to get objects one by one (shortcode)?

Question

JSON

Good afternoon!
As a beginner, I'm stuck a bit with Json parsing by reference.
The crux of the matter is this.
You need to get exchange rates from this link https://api.privatbank.ua/p24api/exchange_rates?js... I
wrote this code.

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

public class JSONParser extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";
    String url = "https://api.privatbank.ua/p24api/exchange_rates?json&date=01.12.2014";

    // constructor
    public JSONParser() {
    }

    public JSONObject getJSONFromUrl(String url) throws JSONException {

        JSONParser jsonParser = new JSONParser();
        JSONObject object = jsonParser.getJSONFromUrl(url);
        String content=object.getString("currency");

//        String content1 = getJSONFromUrl(url).getString("date");
//        if (content1.equals(object)){
//            JSONArray arrayClentHistoryRequest = getJSONFromUrl(url).getJSONArray("exchangeRate");
//            for (int i=0; i<arrayClentHistoryRequest .length();i++)
//            {
//                Toast.makeText(arrayClentHistoryRequest.get(i).getString("currency"), Toast.LENGTH_LONG).show();
//            }

        try {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

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

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
                System.out.println(line);
            }
            is.close();
            json = sb.toString();

        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
            System.out.println("error on parse data in jsonparser.java");
        }

        return jObj;



    }

}

In the comments, the code is written, which I think is needed somewhere here, although I could be wrong.
And how to put it all in some kind of ListView?