Exoplayer not looping the video

You can simply set repeat mode as "Repeat_MODE_ONE".

Example for Kotlin:

  val player: SimpleExoPlayer = ExoPlayerFactory.newSimpleInstance(
        context,
        DefaultRenderersFactory(context),
        DefaultTrackSelector(),
        DefaultLoadControl()
    ).apply {


       repeatMode = Player.REPEAT_MODE_ONE

    }

p.s.The player is from com.google.android.exoplayer2

I discovered that there was some crucial info left out in Exoplayer developers guide. after creating LoopingMediaSource instance, one should not call simpleExoPlayer.prepare(mediaSource); but instead call simpleExoPlayer.prepare(loopingSource);. below is the complete code

     BandwidthMeter bandwidthMeter = new DefaultBandwidthMeter();
    TrackSelection.Factory factory = new AdaptiveTrackSelection.Factory(bandwidthMeter);
    TrackSelector trackSelector = new DefaultTrackSelector(factory);

    simpleExoPlayer = ExoPlayerFactory.newSimpleInstance(this,trackSelector);
    simpleExoPlayer.setPlayWhenReady(true);
    simpleExoPlayerView.setPlayer(simpleExoPlayer);

    // Measures bandwidth during playback. Can be null if not required.
    bandwidthMeter2 = new DefaultBandwidthMeter();

// Produces DataSource instances through which media data is loaded.
    dataSourceFactory = new DefaultDataSourceFactory(this,
      Util.getUserAgent(this, applicationName), bandwidthMeter2);

// Produces Extractor instances for parsing the media data.
    extractorsFactory = new DefaultExtractorsFactory();

        MediaSource mediaSource = new ExtractorMediaSource(videoUri,dataSourceFactory, extractorsFactory, null, null);
    // Loops the video indefinitely.
    LoopingMediaSource loopingSource = new LoopingMediaSource(mediaSource);

    simpleExoPlayer.prepare(loopingSource);

just use player.setRepeatMode(player.REPEAT_MODE_ONE);