VideoPlayerActivity.java

// add your package here

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.graphics.SurfaceTexture;
import android.net.Uri;
import android.os.Bundle;
import android.os.IBinder;
import android.support.v7.app.AppCompatActivity;
import android.view.MotionEvent;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.widget.MediaController;
import android.widget.RelativeLayout;

public class VideoPlayerActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener {

  private TextureView mTextureView;
  private Surface mSurface;
  private MediaController mMediaController;

  private BackgroundAudioService mBackgroundAudioService;
  private boolean mServiceIsBound;

  @Override
  public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    RelativeLayout contentView = new RelativeLayout(this);
    contentView.setOnTouchListener(new View.OnTouchListener() {
      @Override
      public boolean onTouch(View v, MotionEvent event) {
        showControls();
        return false;
      }
    });
    setContentView(contentView);

    mTextureView = new TextureView(this);
    mTextureView.setSurfaceTextureListener(this);
    contentView.addView(mTextureView);

    mMediaController = new MediaController(this);
    mMediaController.setAnchorView(contentView);

    Intent service = new Intent(this, BackgroundAudioService.class);
    bindService(service, mServiceConnection, Context.BIND_AUTO_CREATE);

  }

  private ServiceConnection mServiceConnection = new ServiceConnection() {

    @Override
    public void onServiceConnected(ComponentName className, IBinder service) {
      if(mServiceIsBound){
        return;
      }
      BackgroundAudioService.BackgroundAudioServiceBinder binder = (BackgroundAudioService.BackgroundAudioServiceBinder) service;
      mBackgroundAudioService = binder.getService();
      mMediaController.setMediaPlayer(mBackgroundAudioService);
      mBackgroundAudioService.setSurface(mSurface, false);
      mBackgroundAudioService.playUri(Uri.parse("file:///android_asset/one.mp4"));
      mServiceIsBound = true;
      NotificationProvider.getOngoingVideoNotification(getApplicationContext());
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {
      mServiceIsBound = false;
      NotificationProvider.cancelAllNotifications(getApplicationContext());
      if(mMediaController.isShowing()) {
        mMediaController.setEnabled(false);
        mMediaController.hide();
      }
    }
  };

  private void showControls(){
    if(mServiceIsBound && mMediaController != null && !mMediaController.isShowing()) {
      mMediaController.setEnabled(true);
      mMediaController.show(0);
    }
  }

  private void setSurface(Surface surface, boolean shouldBlock){
    mSurface = surface;
    if(mBackgroundAudioService != null){
      mBackgroundAudioService.setSurface(mSurface, shouldBlock);
    }
  }

  @Override
  public void onPause(){
    super.onPause();
  }

  @Override
  public void onResume(){
    super.onResume();
    showControls();
  }

  @Override
  protected void onDestroy() {
    super.onDestroy();
    NotificationProvider.cancelAllNotifications(getApplicationContext());
    if(mServiceIsBound) {
      mBackgroundAudioService.getExoPlayer().stop();
      mBackgroundAudioService.getExoPlayer().release();
      mBackgroundAudioService.stopSelf();
      unbindService(mServiceConnection);
      mServiceIsBound = false;
    }
  }

  @Override
  public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
    setSurface(new Surface(surfaceTexture), false);
  }

  @Override
  public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int width, int height) {

  }

  @Override
  public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
    setSurface(null, true);
    return true;
  }

  @Override
  public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {

  }

}

I could not able to resolve NotificationProvider in your code. Is there any solution or hint for it?