package com.example.admin.myapplication77;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton)findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view)
    {
     Snackbar.make(view, "Replace with your own
action",Snackbar.LENGTH_LONG).setAction("Action", null).show();
     }
    });
}

public void userReg(View view)
{
    startActivity(new Intent(this,Register.class));

}

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

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

package com.example.admin.myapplication77;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.EditText;

public class Register extends AppCompatActivity {
      EditText ET_NAME,ET_PHONE,ET_EMAIL;
      String name,phone,email;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.register_layout);
    ET_NAME=(EditText)findViewById(R.id.new_name);
    ET_PHONE=(EditText)findViewById(R.id.new_phone);
    ET_EMAIL=(EditText)findViewById(R.id.email);


    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton)findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action",
Snackbar.LENGTH_LONG).setAction("Action", null).show();
        }
    });
    }
public void userReg(View view)
{

  name= ET_NAME.getText().toString();
  phone= ET_PHONE.getText().toString();
  email=ET_EMAIL.getText().toString();
  String method="register";
  BackgroundTask backgroundTask= new BackgroundTask(this);
  backgroundTask.execute(method,name,phone,email);
  finish();
}

}

package com.example.admin.myapplication77;

import android.os.AsyncTask;
import android.content.Context;
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.HttpURLConnection;
import java.net.URLEncoder;

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://10.0.2.2/webapp/register.php";
    String method=params[0];
    if(method.equals("register"))
    {

        String name=params[1];
        String phone=params[2];
        String email=params[3];
        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("user","UTF-8")+"="+URLEncoder.encode(name,"UTF-8")+"&"+URLEncoder.encode("phone","UTF-8")+"="+URLEncoder.encode(phone,"UTF-8")+"&"+ URLEncoder.encode("email","UTF-8")+"="+URLEncoder.encode(email,"UTF-8");
            bufferedWriter.write(data);
            bufferedWriter.flush();
            bufferedWriter.close();
            OS.close();
            InputStream IS = httpURLConnection.getInputStream();
            IS.close();
            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) {
    Toast.makeText(ctx,result,Toast.LENGTH_LONG).show();
}
}

<?php

require"init.php";
if(isset($_POST['submit'])) {
$name=$_POST["user"];
$phone=$_POST["phone"];
$email=$_POST["email"];

$sql_query="insert into user_details values('$name','$phone','$email');";
if(mysqli_query($con,$sql_query))
 {
   echo "<h3>Connection Success</h3>";
 }
 else
 {
  echo "Connection Error!!".mysqli_connect_error();

 }}
 ?>

<?php
$db_name="webappdb";
$mysql_user="root";
$mysql_pass="root";
$server_name="localhost";

$con=mysqli_connect($server_name,$mysql_user,$mysql_pass,$db_name);
if(!$con)
{

 echo "Connection Error!!".mysqli_connect_error();

 }
else
{
 echo "<h3>Connection Success</h3>";
}



?>