Mp3 Audio Play in App

 public class MainActivity extends AppCompatActivity {
  
    private MediaPlayer mMediaPlayer;
    private MediaPlayer.OnCompletionListener mCompletionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            releaseMediaPlayer();
        }
    };

    private AudioManager mAudioManager;

    AudioManager.OnAudioFocusChangeListener mOnAudioFocusChangeListener =
            new AudioManager.OnAudioFocusChangeListener() {
                public void onAudioFocusChange(int focusChange) {

                    if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT || focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK) {
                        // Pause playback && Duck:- Lower the volume, keep playing
                        mMediaPlayer.pause();
                        mMediaPlayer.seekTo(0);
                    } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
                        // Your app has been granted audio focus again
                        // Raise volume to normal, restart playback if necessary
                        mMediaPlayer.start();
                    } else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
                        releaseMediaPlayer();

                    }
                }
            };
            
   private Button mPlayButton;         

 
  @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
         mAudioManager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
         mPlayButton = findViewById(R.id.btn);
    }
  
   @Override
    public void onStop() {
        super.onStop();
        releaseMediaPlayer();
    }

    /**
     * Clean up the media player by releasing its resources.
     */

    private void releaseMediaPlayer() {
        // If the media player is not null, then it may be currently playing a sound.
        if (mMediaPlayer != null) {
            // Regardless of the current state of the media player, release its resources
            // because we no longer need it.
            mMediaPlayer.release();

            // Set the media player back to null. For our code, we've decided that
            // setting the media player to null is an easy way to tell that the media player
            // is not configured to play an audio file at the moment.
            mMediaPlayer = null;

            // Abandon audio focus when playback complete
            mAudioManager.abandonAudioFocus(mOnAudioFocusChangeListener);
        }
    }

    private void playMusic(int position){
       // Word word = words.get(position);
        //Log.v("NumbersActivity", "Current word: " + word.toString());
        releaseMediaPlayer();

        // Request audio focus for playback
        int result = mAudioManager.requestAudioFocus(mOnAudioFocusChangeListener,
                // Use the music stream.
                AudioManager.STREAM_MUSIC,
                // Request permanent focus.
                AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);

        if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
            // Start playback

            int[] msc = {R.raw.click,R.raw.right,R.raw.wrong,R.raw.snd_bg};


            mMediaPlayer = MediaPlayer.create(this, msc[position]);
            mMediaPlayer.start();
            mMediaPlayer.setOnCompletionListener(mCompletionListener);
        }
    }
  
 }