This is an example exercising GET Method and POST Method in Android by using HttpURLConnection class.

Survey

package com.mitgsl.johnsonyeap.androidassignment2;

import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;


public class Survey extends Activity implements View.OnClickListener{

    private TextView question1, question2, question3;
    private EditText answer1, answer2, answer3;
    private ArrayList<String> answerArray = new ArrayList<String>();
    public JSONArray jArray;
    private static final String SURVEY = "https://gsl-poll-app.herokuapp.com/surveys/1/";
    private static final String DEBUG_TAG = "HttpExample";
    private String dataSet;


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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.survey, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        return (id == R.id.action_settings) || super.onOptionsItemSelected(item);
    }

    @Override
    public void onClick(View v) {
        switch(v.getId()) {
            case R.id.bSubmit:
                new postData().execute(SURVEY);
                Toast.makeText(getApplicationContext(), "Submitted successfully", Toast.LENGTH_LONG).show();
                break;
        }
    }

    private void initialize() {
        Button submit = (Button) findViewById(R.id.bSubmit);
        question1 = (TextView) findViewById(R.id.tvQ1);
        question2 = (TextView) findViewById(R.id.tvQ2);
        question3 = (TextView) findViewById(R.id.tvQ3);
        answer1 = (EditText) findViewById(R.id.etA1);
        answer2 = (EditText) findViewById(R.id.etA2);
        answer3 = (EditText) findViewById(R.id.etA3);
        submit.setOnClickListener(this);

        ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();

        if(networkInfo != null && networkInfo.isConnected())
            new getData().execute(SURVEY);
        else
            Toast.makeText(getApplicationContext(), "Unable to retrieve web page", Toast.LENGTH_LONG).show();
    }

    private class getData extends AsyncTask<String, Void, String> {
        String question;
        int id;

        @Override
        protected String doInBackground(String... urls) {
            try {
                dataSet = downloadUrl(urls[0]);

            } catch(IOException e) {
                return "Unable to retrieve web page. URL may be invalid";
            }
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            try {
                jArray = new JSONArray(dataSet);
                for(int x = 0; x < jArray.length(); x++) {
                    JSONObject jObject = jArray.getJSONObject(x);
                    id = jObject.getInt("id");
                    question = jObject.getString("question_text");
                    switch (id) {
                        case 1:
                            question1.setText(question);
                            break;
                        case 2:
                            question2.setText(question);
                            break;
                        case 3:
                            question3.setText(question);
                            break;
                    }
                }
            } catch (JSONException e) {
                throw new RuntimeException(e);
            }
        }
    }

    //Fetches and processes the web page content and passes back a result string.
    private String downloadUrl(String myurl) throws IOException {
        String contentAsString;
        InputStream is = null;
        // Only display the first 500 characters of the retrieved
        // web page content.
        int len = 500;

        try {
            URL url = new URL(myurl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            // Starts the query
            conn.connect();
            int response = conn.getResponseCode();
            Log.d(DEBUG_TAG, "The GET response is: " + response);
            is = conn.getInputStream();

            // Convert the InputStream into a string
            contentAsString = readIt(is, len);
            return contentAsString;

            // Makes sure that the InputStream is closed after the app is
            // finished using it.
        } finally {
            if (is != null) {
                is.close();
            }
        }
    }

    // Reads an InputStream and converts it to a String.
    public String readIt(InputStream stream, int len) throws IOException {
        Reader reader;
        reader = new InputStreamReader(stream, "UTF-8");
        char[] buffer = new char[len];
        reader.read(buffer);
        return new String(buffer);
    }

    private class postData extends AsyncTask<String, Void, Void> {

        @Override
        protected Void doInBackground(String... urls)  {
            answerArray.add(answer1.getText().toString());
            answerArray.add(answer2.getText().toString());
            answerArray.add(answer3.getText().toString());

            HttpURLConnection c = null;
            OutputStream os;

            Integer question = 1;
            JSONObject jResponse = new JSONObject();
            JSONObject jRespondent = new JSONObject();
            JSONArray jAnswers = new JSONArray();

            try {
                jRespondent.put("first_name", "Johnson");
                jRespondent.put("last_name", "Yeap");
                for (String answer : answerArray) {
                    JSONObject jAnswer = new JSONObject();
                    jAnswer.put("question", (question++).toString());
                    jAnswer.put("response_text", answer);
                    jAnswers.put(jAnswer);
                }
                jRespondent.put("question_responses", jAnswers);
                //passed
                jResponse.put("response", jRespondent);
            } catch (JSONException e) {
                e.printStackTrace();
            }

            byte[] data =  jResponse.toString().getBytes();

            try {
                URL url = new URL(urls[0]);
                c = (HttpURLConnection) url.openConnection();
                c.setDoOutput(true);
                c.setFixedLengthStreamingMode(data.length);
                c.connect();
                os = c.getOutputStream();

                if (os != null) {
                    os.write(data);
                    os.close();
                }

                    int responseCode = c.getResponseCode();
                    Log.d(DEBUG_TAG, "POST Response Code = " + responseCode);

                InputStream is = c.getInputStream();
                String result = readIt(is, 1000);
                Log.d(DEBUG_TAG, "Response = " + result);

                    responseCode = c.getResponseCode();
                    Log.d(DEBUG_TAG, "GET Response Code = " + responseCode);

            } catch (MalformedURLException e) {
                //If the URL is not a valid URL.
                e.printStackTrace();
            } catch (IOException e) {
                //If an error prevented opening or writing to the stream.
                e.printStackTrace();
            }

             finally {
                //This clause ensures that disconnect() is always run last,
                //even after an exception is caught. You should wrap
                //reader.readLine() like this too.
                if (c != null)
                    c.disconnect();
            }
            return null;
        }
    }
}