Singleton Sound Player in Android

AnyWhere.java

SoundPoolManager.getInstance().play(getContext(), R.raw.any_sound);
MediaPlayerManager.getInstance().play(getContext(), R.raw.any_sound);

MediaPlayerManager.java

package com.akexorcist.myapplication;

import android.content.Context;
import android.media.MediaPlayer;

/**
 * Created by Akexorcist on 4/3/2017 AD.
 */

public class MediaPlayerManager {
    private static MediaPlayerManager manager;

    public static MediaPlayerManager getInstance() {
        if (manager == null) {
            manager = new MediaPlayerManager();
        }
        return manager;
    }

    private MediaPlayer mediaPlayer;

    public void play(Context context, int resId) {
        play(context, resId, null, null);
    }

    public void play(Context context, int resId, MediaPlayer.OnCompletionListener completionListener) {
        play(context, resId, completionListener, null);
    }

    public void play(Context context, int resId, MediaPlayer.OnErrorListener errorListener) {
        play(context, resId, null, errorListener);
    }

    public void play(Context context, int resId, MediaPlayer.OnCompletionListener completionListener, MediaPlayer.OnErrorListener errorListener) {
        if (mediaPlayer != null) {
            if (mediaPlayer.isPlaying()) {
                mediaPlayer.stop();
            }
            mediaPlayer.release();
            mediaPlayer = null;
        }
        mediaPlayer = MediaPlayer.create(context.getApplicationContext(), resId);
        mediaPlayer.setOnCompletionListener(completionListener);
        mediaPlayer.setOnErrorListener(errorListener);
        mediaPlayer.start();
    }
}

SoundPoolManager.java

package com.akexorcist.myapplication;

import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;

/**
 * Created by Akexorcist on 4/3/2017 AD.
 */

public class SoundPoolManager {
    private static SoundPoolManager manager;

    public static SoundPoolManager getInstance() {
        if (manager == null) {
            manager = new SoundPoolManager();
        }
        return manager;
    }

    private SoundPool soundPool;
    private int currentSoundId = -1;

    public SoundPoolManager() {
        soundPool = new SoundPool(1, AudioManager.STREAM_MUSIC, 0);
    }

    public void play(Context context, int resid) {
        play(context, resid);
    }

    public void play(Context context, int resId, SoundPool.OnLoadCompleteListener listener) {
        if (currentSoundId != -1) {
            soundPool.stop(currentSoundId);
        }
        soundPool.load(context.getApplicationContext(), resId, 0);
        soundPool.play(currentSoundId, 1, 1, 1, 0, 1);
        soundPool.setOnLoadCompleteListener(listener);
    }
}

At line 29 StackOverFlow i believe? There should be last parameter with null as listener?