Android - sending HTTP parameters via POST method easily

    package demo.com.mysqldbdemo;

import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;

import javax.net.ssl.HttpsURLConnection;

/**
 * Created by Ahmadzai on 7/10/2017.
 */

public class BackgroundTask extends AsyncTask<String, Void, String> {

    Context ctx;
    BackgroundTask(Context ctx)
    {
        this.ctx = ctx;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        String reg_url = "http://192.168.8.100:8081/webapp/register.php";
        String login_url = "http://localhost/webapp/login.php";
        String method = params[0];
        if (method.equals("register"))
        {
            String name = params[1];
            String user_name = params[2];
            String user_pass = params[3];

            try {
                URL url = new URL(reg_url);
                HttpsURLConnection httpsURLConnection = (HttpsURLConnection) url.openConnection();
                httpsURLConnection.setRequestMethod("POST");
                httpsURLConnection.setDoOutput(true);
                OutputStream OS = httpsURLConnection.getOutputStream();
                BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(OS,"UTF-8"));
                String data = URLEncoder.encode("user","UTF-8") + "=" +URLEncoder.encode(name,"UTF-8")+"&"+
                        URLEncoder.encode("user_name","UTF-8") + "=" +URLEncoder.encode(user_name,"UTF-8")+"&"+
                        URLEncoder.encode("user_pass","UTF-8") + "=" +URLEncoder.encode(user_pass,"UTF-8");
                bufferedWriter.write(data);
                bufferedWriter.flush();
                bufferedWriter.close();
                OS.close();

                InputStream IS = httpsURLConnection.getInputStream();
                IS.close();
                return "Registration succeed ....";

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    @Override
    protected void onProgressUpdate(Void... values) {
        super.onProgressUpdate(values);
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(ctx,result,Toast.LENGTH_LONG).show();
    }
}

I want to insert data into mysql table, as this code does not have any error but when I press the register button in the interface the application stops running when I want to debug the application it runs till "HttpsURLConnection httpsURLConnection = (HttpsURLConnection) url.openConnection();" line of code after this it stops debugging. Anyone can help me in this regard, please? I have been using stackoverflow answers but this is my first try on questioning, sorry for the inconvenience.