I wanted to connect android studio to mysql

Question

I wanted to insert data in mysql and also to retrieve, modify and delete rows in it. I don't have any programming knowledge, just a little database manipulation. This android studio is a whole new thing for me and its like i'm having problems from the tutorials regarding on connecting android studio to mysql. I tried to use the ip add of my computer, the 10.0.2.2 , the 127.0.0.1 and even registering for a free web hosting but it still doesn't insert data.

Another thing the dialog box that should display the status of registration doesn't work.

One last thing I know that the mistake is in this code because when i looked on their tutorial it worked but i can't figure it out why it doesn't work on me.

I really appreciate any help you can provide.

here's the php file

conn.php
<?php
$db_name = "dbapp";
$mysql_username="root";
$mysql_password="";
$server_name="localhost";
$con = mysqli_connect($server_name,$mysql_username,$mysql_password,$db_name);
?>


register.php
<?php
require "conn.php";
$f_name=$_POST["first_name"];
$m_name=$_POST["middle_name"];
$l_name=$_POST["last_name"];
$email_add=$_POST["emailadd"];
$user_name=$_POST["username"];
$user_pass=$_POST["userpass"];

$sql_query = "insert into tbluser (f_name, m_name, l_name, user_emadd, user_name, user_pass) values('$fname','$mname','$lname','email_add','$user_name','user_pass')";
?>

here's some of the android studio files

Register.java

package com.example.*****.myapplication;
// Above code is not really asterisk, i just wanna hide it..
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;


public class Register extends Activity{

    EditText ET_FNAME,ET_MNAME,ET_LNAME,ET_EMAIL,ET_USERNAME,ET_PASS;
    String txtfname, txtmname, txtlname, txtusername, txtemail, txtpass;


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

    ET_FNAME = (EditText)findViewById(R.id.et_fname);
    ET_MNAME = (EditText)findViewById(R.id.et_mname);
    ET_LNAME = (EditText)findViewById(R.id.et_lname);
    ET_EMAIL = (EditText)findViewById(R.id.et_email);
    ET_USERNAME = (EditText)findViewById(R.id.et_username);
    ET_PASS = (EditText)findViewById(R.id.etpassword);

}


public void userReg(View view){

    txtfname = ET_FNAME.getText().toString();
    txtmname = ET_MNAME.getText().toString();
    txtlname = ET_LNAME.getText().toString();
    txtemail = ET_EMAIL.getText().toString();
    txtusername = ET_USERNAME.getText().toString();
    txtpass = ET_PASS.getText().toString();


    String method = "register";
    BackgroundWorker backgroundWorker = new BackgroundWorker(this);
    backgroundWorker.execute(method,txtfname,txtmname, txtlname, txtemail, txtusername,txtpass);
    finish();

}
}

here's another java class BackgroundWorker.java

package com.example.*****.myapplication;

import android.app.AlertDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;


public class BackgroundWorker extends AsyncTask<String,Void,String> {
AlertDialog alertDialog;
Context ctx;

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

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

@Override
protected String doInBackground(String... params) {
    String reg_url = "http://10.0.2.2/myapp/register.php";
    String login_url = "http://10.0.2.2/myapp/login.php";

    String method = params[0];
    if (method.equals("register")) {
        String fname = params[1];
        String mname = params[2];
        String lname = params[3];
        String emailadd = params[4];
        String username = params[5];
        String userpass = params[6];

              try {
                   URL url = new URL(reg_url);
                   HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                   httpURLConnection.setRequestMethod("POST");
                   httpURLConnection.setDoOutput(true);
                   OutputStream OS = httpURLConnection.getOutputStream();
                   BufferedWriter bufferedwriter = new BufferedWriter(new OutputStreamWriter(OS, "UTF-8"));
                   String data = URLEncoder.encode("f_name", "UTF-8") + "=" + URLEncoder.encode(fname, "UTF-8") + "&" +
                   URLEncoder.encode("m_name", "UTF-8") + "=" + URLEncoder.encode(mname, "UTF-8") + "&" +
                   URLEncoder.encode("l_name", "UTF-8") + "=" + URLEncoder.encode(lname, "UTF-8") + "&" +
                   URLEncoder.encode("email_add", "UTF-8") + "=" + URLEncoder.encode(emailadd, "UTF-8") + "&" +
                   URLEncoder.encode("user_name", "UTF-8") + "=" + URLEncoder.encode(username, "UTF-8") + "&" +
                   URLEncoder.encode("user_pass", "UTF-8") + "=" + URLEncoder.encode(userpass, "UTF-8");



                  bufferedwriter.write(data);
                   bufferedwriter.flush();
                   bufferedwriter.close();
                    OS.close();
                   InputStream IS = httpURLConnection.getInputStream();
                   IS.close();

                  httpURLConnection.disconnect();
                    return "Registration Success";


} 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) {

    if(result.equals("Registration Success"))
    {
    Toast.makeText(ctx, result, Toast.LENGTH_LONG).show();
    }
    else
    {
    alertDialog.setMessage(result);
    alertDialog.show();
     }
    }
}

here are the column name in mysql, it has userid as primary key and autocrement.

 fname
 mname
 lname
 email_add
 user_name
 user_pass