Android Exoplayer - Different URLs for different video quality and change manually

I am using exoplayer in my application. I am using it to play video from a url. What i am trying to do is that i have three different urls for high,medium and low quality of same the video, and i would like to let the user to be able to change the video quality manually.

{
     "lowQualityUrl":"string url",
     "mediumQualityUrl":"string url",
     "highQualityUrl":"string url"
}

In JWplayer there is an option to add different sources/url for different qualities. Is there something similar that can be done in exoplayer...?

Edit : I don't want to play videos one after another. I just want to switch to a different quality of the same video, like in youtube. But instead of using a single url for the source, what i have are 3 different urls for 3 qualities(low,medium,high) of the same video.

I found a solution or rather a workaround for the issue. I am using the exoplayer inside a recylcerview. This code might need some optimization.

I got this idea from another answer which was under this question,which had this github link, but i think the author deleted it. What i did was create a class for keeping all the urls for a particular video. Then showing a Spinner above the exoplayer, and when user selects a particular quality then i prepare the exoplayer with the new URL, and then seekto to the previously playing position. You can ignore the StringUtils methods.

VideoPlayerConfig.kt

object VideoPlayerConfig {
//Minimum Video you want to buffer while Playing
val MIN_BUFFER_DURATION = 3000
//Max Video you want to buffer during PlayBack
val MAX_BUFFER_DURATION = 5000
//Min Video you want to buffer before start Playing it
val MIN_PLAYBACK_START_BUFFER = 1500
//Min video You want to buffer when user resumes video
val MIN_PLAYBACK_RESUME_BUFFER = 5000
} 

VideoQuality.kt

You can change this class according to your need. I need to store exactly 3 urls for low,medium and high quality urls. And i needed to show them in that order as well in the spinner.

class VideoQuality {
private val videoQualityUrls = HashMap<String, String>()

companion object {
    val LOW = getStringResource(R.string.low)
    val MEDIUM = getStringResource(R.string.medium)
    val HIGH = getStringResource(R.string.high)
}

val qualityArray
    get() = arrayListOf<String>().apply {
        if (hasQuality(LOW)) add(LOW)
        if (hasQuality(MEDIUM)) add(MEDIUM)
        if (hasQuality(HIGH)) add(HIGH)
    }
var defaultVideoQuality: String? = HIGH

var lowQuality: String?
    set(value) {
        setVideoQualityUrl(LOW, value)
    }
    get() = videoQualityUrls[LOW] ?: ""
var mediumQuality: String?
    set(value) {
        setVideoQualityUrl(MEDIUM, value)
    }
    get() = videoQualityUrls[MEDIUM] ?: ""
var highQuality: String?
    set(value) {
        setVideoQualityUrl(HIGH, value)
    }
    get() = videoQualityUrls[HIGH] ?: ""

private fun setVideoQualityUrl(quality: String?, url: String?) {
    if (url != null && quality != null) {
        videoQualityUrls[quality] = url
    }
}

private fun hasQuality(quality: String?): Boolean {
    if (videoQualityUrls[quality] == null) {
        return false
    }
    return true
}

fun getVideoQualityUrl(quality: String?): String? {
    return videoQualityUrls[quality]
}
}

Methods to implement for the exoplayer

private fun initializePlayer() {
    if (exoPlayer == null) {

        val loadControl = DefaultLoadControl.Builder()
            .setBufferDurationsMs(2 * VideoPlayerConfig.MIN_BUFFER_DURATION, 2 * VideoPlayerConfig.MAX_BUFFER_DURATION, VideoPlayerConfig.MIN_PLAYBACK_START_BUFFER, VideoPlayerConfig.MIN_PLAYBACK_RESUME_BUFFER)
            .createDefaultLoadControl()
        //Create a default TrackSelector
        val videoTrackSelectionFactory = AdaptiveTrackSelection.Factory()
        val trackSelector = DefaultTrackSelector(videoTrackSelectionFactory)
        exoPlayer = ExoPlayerFactory.newSimpleInstance(itemView.context, DefaultRenderersFactory(itemView.context), trackSelector, loadControl)
        exoPlayer!!.addListener(PlayEventListener())
        val videoQualityInfo:VideoQuality = videoListVideoDataHolderData!!.videoQualityUrls //Just an object that i created and stored in a dataHolder for this view.
        val url = videoQualityInfo.getVideoQualityUrl(videoQualityInfo.defaultVideoQuality) ?: ""
        preparePlayer(url)
    }
}

private fun preparePlayer(url: String) {

    if (url.isNotEmpty()) {
        val mediaSource = buildMediaSource(StringUtils.makeHttpUrl(url))
        exoPlayer?.prepare(mediaSource)
        videoView.player = exoPlayer
    } else {
        Log.d(APPTAG, "NO DEFAULT URL")
    }
}
private fun buildMediaSource(url: String): ProgressiveMediaSource {
    val mUri: Uri = Uri.parse(url)
    val dataSourceFactory = DefaultDataSourceFactory(
        itemView.context,
        Util.getUserAgent(itemView.context, getStringResource(R.string.app_name))
    )
    val videoSource = ProgressiveMediaSource.Factory(dataSourceFactory)
        .createMediaSource(mUri)
    return videoSource
}

And then in the Spinner/QualitySelector's OnItemSelectedListener

videoQualitySpinner.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
        override fun onNothingSelected(parent: AdapterView<*>?) {

        }

        override fun onItemSelected(parent: AdapterView<*>?, view: View?, position: Int, id: Long) {
            val currentTime = exoPlayer?.currentPosition
            val isReadyToPlay = exoPlayer?.playWhenReady
            val urlToBuild = when (videoQualityUrls.qualityArray[position]) {
                VideoQuality.LOW -> videoQualityUrls.lowQuality
                VideoQuality.MEDIUM -> videoQualityUrls.mediumQuality
                else -> videoQualityUrls.highQuality
            }
            Log.d(APPTAG, "VIDEO DETAILS :::: ${currentTime} ${isReadyToPlay} ${urlToBuild}")
            if (!urlToBuild.isNullOrEmpty()) {
                val mediaSource = buildMediaSource(StringUtils.makeHttpUrl(urlToBuild))
                exoPlayer?.prepare(mediaSource)
                exoPlayer?.playWhenReady = isReadyToPlay ?: false
                exoPlayer?.seekTo(currentTime ?: 0)
            }

        }
    }