Problem with Audio in a basic music player in Android Studio

I created a basic music player app in Android Studio with the music file stored in the raw directory under resources and Mp3 format.
the issue is that though the toast inside the event listener gets displayed , the audio is not playing except once(i really do not know how).
the code is as below.

the manifest file

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.basicmusicplayer">

    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"

        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

the xml file

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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"
    android:layout_gravity="center"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/greetings"
        android:textSize="30sp"
        android:textStyle="bold"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="221dp"
        android:layout_height="298dp"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="104dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.505"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        app:srcCompat="@android:drawable/ic_media_play" />

    <Button
        android:id="@+id/pause"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginBottom="8dp"
        android:text="@string/pause"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@+id/stop"
        app:layout_constraintHorizontal_bias="0.565"
        app:layout_constraintStart_toEndOf="@+id/play"
        app:layout_constraintTop_toBottomOf="@+id/imageView"
        app:layout_constraintVertical_bias="0.205" />

    <Button
        android:id="@+id/play"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        android:text="@string/play"
        app:layout_constraintBaseline_toBaselineOf="@+id/pause"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/stop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginRight="8dp"
        android:text="@string/stop"
        app:layout_constraintBaseline_toBaselineOf="@+id/pause"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

the java code

package com.example.basicmusicplayer;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.content.Context;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    MediaPlayer player;

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

        /*
         an object of class MediaPlayer created named player
         a mp3 file is added to the object using create method*/
        player = MediaPlayer.create(this, R.raw.adele);

//        setting up  inline event listeners to the button
//        first comes the play button
        Button play_music = findViewById(R.id.play);
        play_music.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "Playing sound",Toast.LENGTH_SHORT).show();
                player.start();

            }
        });

//        adding event listener on pause button
        Button pause_music = findViewById(R.id.pause);
        pause_music.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "paused sound",Toast.LENGTH_SHORT).show();
                player.pause();

            }
        });

//        adding event listener for stop button
        Button stop_music = findViewById(R.id.stop);
        stop_music.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getApplicationContext(), "stopped sound",Toast.LENGTH_SHORT).show();
                player.stop();

            }
        });



    }
}

 private MediaPlayer mp;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button b = (Button) findViewById(R.id.button1);
       
        final TextView t = (TextView) findViewById(R.id.textView1);

        b.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                stopPlaying();
                mp = MediaPlayer.create(PlayaudioActivity.this, R.raw.far);
                mp.start();
            }

        });
    }

    private void stopPlaying() {
        if (mp != null) {
            mp.stop();
            mp.release();
            mp = null;
       }
    }