BASIC play mp3 android studio

create raw folder  value resource type raw select kare

package com.example.viraj.mediaplayerapp;

import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

//import static com.example.viraj.mediaplayerapp.R.raw.ashique;


public class MainActivity extends AppCompatActivity {
    private MediaPlayer mediaPlayer;
    private Button playbutton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mediaPlayer = new MediaPlayer();
        mediaPlayer = MediaPlayer.create(MainActivity.this,R.raw.haa);

        playbutton = (Button) findViewById(R.id.MusicPlay);
        playbutton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (mediaPlayer.isPlaying()) {
                    //stop music and give option
                    pausemusic();
                }
                else
                {
                    startmusic();
                }
            }
        });

    }
    //create method in side of our class
    public void pausemusic() {
        if (mediaPlayer != null)
            mediaPlayer.pause();
        playbutton.setText("PLAY MUSIC");
    }

    public void startmusic()

    {
        if (mediaPlayer != null) {
            mediaPlayer.start();
            playbutton.setText("PAUSE MUSIC");
        }

    }
}

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:app="http://schemas.android.com/apk/res-auto"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context="com.example.viraj.mediaplayerapp.MainActivity">

    <Button

        android:id="@+id/MusicPlay"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginBottom="8dp"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:layout_marginTop="8dp"

        android:text="PLAY"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>