Minimum ExoPlayer video playing

MainActivity.java

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.support.annotation.Nullable;
import android.view.SurfaceView;

import com.google.android.exoplayer2.C;
import com.google.android.exoplayer2.DefaultLoadControl;
import com.google.android.exoplayer2.ExoPlayerFactory;
import com.google.android.exoplayer2.SimpleExoPlayer;
import com.google.android.exoplayer2.extractor.DefaultExtractorsFactory;
import com.google.android.exoplayer2.source.ExtractorMediaSource;
import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
import com.google.android.exoplayer2.util.Util;

import org.androidannotations.annotations.AfterViews;
import org.androidannotations.annotations.EActivity;
import org.androidannotations.annotations.ViewById;

import java.io.IOException;

@EActivity(R.layout.activity_main)
public class MainActivity extends Activity {
    private SimpleExoPlayer player;

    @ViewById
    SurfaceView surfaceView;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        player = ExoPlayerFactory.newSimpleInstance(this, new DefaultTrackSelector(), new DefaultLoadControl());
        player.setAudioStreamType(C.STREAM_TYPE_MUSIC);
        player.prepare(new ExtractorMediaSource(Uri.parse(VIDEO_URL), new DefaultDataSourceFactory(this, Util.getUserAgent(this, "Test")), new DefaultExtractorsFactory(), new Handler(), new ExtractorMediaSource.EventListener() {
            @Override
            public void onLoadError(IOException error) {
                error.printStackTrace();
            }
        }));
    }

    @AfterViews
    void init() {
        player.setVideoSurfaceView(surfaceView);
    }

    @Override
    protected void onResume() {
        super.onResume();
        player.setPlayWhenReady(true);
    }

    @Override
    protected void onPause() {
        player.setPlayWhenReady(false);
        super.onPause();
    }

    @Override
    protected void onDestroy() {
        player.release();
        super.onDestroy();
    }
}