ExoplayergithubSavingState

import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import com.google.android.exoplayer2.DefaultLoadControl;
import com.google.android.exoplayer2.DefaultRenderersFactory;
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.source.MediaSource;
import com.google.android.exoplayer2.trackselection.AdaptiveTrackSelection;
import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
import com.google.android.exoplayer2.trackselection.TrackSelection;
import com.google.android.exoplayer2.trackselection.TrackSelector;
import com.google.android.exoplayer2.ui.PlayerView;
import com.google.android.exoplayer2.upstream.BandwidthMeter;
import com.google.android.exoplayer2.upstream.DataSource;
import com.google.android.exoplayer2.upstream.DefaultBandwidthMeter;
import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
import com.google.android.exoplayer2.upstream.DefaultHttpDataSourceFactory;
import com.google.android.exoplayer2.util.Util;

public class MainActivity extends AppCompatActivity {

    private SimpleExoPlayer player;
    private PlayerView mPlayerView;

    int currentWindow;
    long playBackPosition;

    // autoplay = false
    private boolean autoPlay = false;

    // constant fields for saving and restoring bundle
    public static final String AUTOPLAY = "autoplay";
    public static final String CURRENT_WINDOW_INDEX = "current_window_index";
    public static final String PLAYBACK_POSITION = "playback_position";
    private final String PATH = "file:///android_asset/videoplayback.mp4";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mPlayerView = findViewById(R.id.playerview);
        Log.e("ON_CREATE", "OnCreate");

        if (savedInstanceState != null) {
            Log.e("ON_CREATE", "OnsaveInstance not null");
            playBackPosition = savedInstanceState.getLong(PLAYBACK_POSITION);
            currentWindow = savedInstanceState.getInt(CURRENT_WINDOW_INDEX);
            autoPlay = savedInstanceState.getBoolean(AUTOPLAY);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        Log.e("ON_PAUSE", "OnPause");
        releasePlayer();
    }

    @Override
    protected void onResume() {
        super.onResume();
        Log.e("ON_RESUME", "onResume");
        initializePlayer();
    }



    void initializePlayer(){
        Uri uri = Uri.parse(PATH);
        //create exoplayer object
        BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();

        TrackSelection.Factory videoTrackSelectionFactory = new AdaptiveTrackSelection.Factory(bandwidthMeter);
        TrackSelector trackSelector = new DefaultTrackSelector(videoTrackSelectionFactory);
        player = ExoPlayerFactory.newSimpleInstance(this,trackSelector);

        MediaSource mediaSource = buildMediaSource(uri);
        //attach the player to the view
        mPlayerView.setPlayer(player);
        player.setPlayWhenReady(autoPlay);

        player.seekTo(currentWindow,playBackPosition);



        player.prepare(mediaSource);
    }

    /*
     * This method returns ExtractorMediaSource or one of its compositions
     * ExtractorMediaSource is suitable for playing regular files like (mp4, mp3, webm etc.)
     * This is appropriate for the baking app project, since all recipe videos are not in adaptive formats (i.e. HLS, Dash etc)
     */
    private MediaSource buildMediaSource(Uri uri) {
        DefaultExtractorsFactory extractorSourceFactory = new DefaultExtractorsFactory();
//        DefaultHttpDataSourceFactory dataSourceFactory = new DefaultHttpDataSourceFactory("ua");

        String userAgent = Util.getUserAgent(this, getApplicationContext().getApplicationInfo().packageName);
        DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(this, userAgent);

//        ExtractorMediaSource audioSource = new ExtractorMediaSource(uri, dataSourceFactory, extractorSourceFactory, null, null);
        // this return a single mediaSource object. i.e. no next, previous buttons to play next/prev media file
        return new ExtractorMediaSource(uri, dataSourceFactory, extractorSourceFactory, null, null);
    }

    private void releasePlayer() {
        if (player != null) {
            Log.e("RELEASE PLAYER", "releasing player not null");
            // save the player state before releasing its resources
            playBackPosition = player.getCurrentPosition();
            currentWindow = player.getCurrentWindowIndex();
            autoPlay = player.getPlayWhenReady();
            player.release();
            player = null;
            Log.e("RELEASE PLAYER", " player set to null");
        }
    }

    @Override
    protected void onStop() {
        super.onStop();
        Log.e("OnSTOP", "ON STOP");

    }

    // save app state before all members are gone forever :D


    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        Log.e("SVE INSTANCE", "onsaveInstanceState player not null");
        if(player == null){
            Log.e("SVE INSTANCE", "onsaveInstanceState player null");
            outState.putLong(PLAYBACK_POSITION, playBackPosition);
            outState.putInt(CURRENT_WINDOW_INDEX, currentWindow);
            outState.putBoolean(AUTOPLAY, autoPlay);
        }
    }
}