안드로이드 - DownloadManager로 파일 다운받는 방법

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

    <Button
            android:id="@+id/downloadBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Download"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

    <Button
            android:id="@+id/statusBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Status"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@id/downloadBtn"/>

    <Button
            android:id="@+id/cancelBtn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Cancel"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toBottomOf="@id/statusBtn"/>

</androidx.constraintlayout.widget.ConstraintLayout>

<uses-permission android:name="android.permission.INTERNET"/>

downloadBtn.setOnClickListener {
    downloadImage()
}

private fun downloadImage() {
    val file = File(getExternalFilesDir(null), "dev_submit.mp4")
    val youtubeUrl = "https://r2---sn-oguelney.googlevideo.com/videoplayback?expire=1547361698&ratebypass=yes&ipbits=0&txp=5431432&fvip=2&sparams=clen,dur,ei,expire,gir,id,ip,ipbits,itag,lmt,mime,mip,mm,mn,ms,mv,pl,ratebypass,requiressl,source,usequic&dur=2487.205&source=youtube&id=o-AFU5WYmppmSyvhuN-vYHnA9zb_qazPL5JANaBNepI9ZF&requiressl=yes&lmt=1541762056298111&itag=18&ip=52.78.151.237&clen=106473489&signature=02FE1AD7C3C0FDFB173383A9D48A1374FDDE9470.31A7D7D3F98045946B0DD3C07436A241B223B84D&ei=Qok6XOqPGI3DqQHxlL_4CA&pl=24&key=cms1&c=WEB&gir=yes&mime=video%2Fmp4&redirect_counter=1&cm2rm=sn-oguy67l&req_id=471900e67ee3a3ee&cms_redirect=yes&mip=182.228.195.55&mm=34&mn=sn-oguelney&ms=ltu&mt=1547339611&mv=u&usequic=no"

    val request = DownloadManager.Request(Uri.parse(youtubeUrl))
        .setTitle("Downloading a video")
        .setDescription("Downloading Dev Summit")
        .setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE)
        .setDestinationUri(Uri.fromFile(file))
        .setRequiresCharging(false)
        .setAllowedOverMetered(true)
        .setAllowedOverRoaming(true)

    downloadId = downloadManager.enqueue(request)
    Log.d(TAG, "path : " + file.path)
}

statusBtn.setOnClickListener {
    val status = getStatus(downloadId)
    Toast.makeText(this, status, Toast.LENGTH_SHORT).show()
}

private fun getStatus(id: Long): String {
    val query: DownloadManager.Query = DownloadManager.Query()
    query.setFilterById(id)
    var cursor = downloadManager.query(query)
    if (!cursor.moveToFirst()) {
        Log.e(TAG, "Empty row")
        return "Wrong downloadId"
    }

    var columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
    var status = cursor.getInt(columnIndex)
    var columnReason = cursor.getColumnIndex(DownloadManager.COLUMN_REASON)
    var reason = cursor.getInt(columnReason)
    var statusText: String

    when (status) {
        DownloadManager.STATUS_SUCCESSFUL -> statusText = "Successful"
        DownloadManager.STATUS_FAILED -> {
            statusText = "Failed: $reason"
        }
        DownloadManager.STATUS_PENDING -> statusText = "Pending"
        DownloadManager.STATUS_RUNNING -> statusText = "Running"
        DownloadManager.STATUS_PAUSED-> {
            statusText = "Paused: $reason"
        }
        else -> statusText = "Unknown"
    }

    return statusText
}

cancelBtn.setOnClickListener {
    if (downloadId != -1L) {
        downloadManager.remove(downloadId)
    }
}

val intentFilter = IntentFilter()
intentFilter.addAction(DownloadManager.ACTION_DOWNLOAD_COMPLETE)
intentFilter.addAction(DownloadManager.ACTION_NOTIFICATION_CLICKED)
registerReceiver(onDownloadComplete, intentFilter)

private val onDownloadComplete = object : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        val id = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1)
        if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(intent.action)) {
            if (downloadId == id) {
                val query: DownloadManager.Query = DownloadManager.Query()
                query.setFilterById(id)
                var cursor = downloadManager.query(query)
                if (!cursor.moveToFirst()) {
                    return
                }

                var columnIndex = cursor.getColumnIndex(DownloadManager.COLUMN_STATUS)
                var status = cursor.getInt(columnIndex)
                if (status == DownloadManager.STATUS_SUCCESSFUL) {
                    Toast.makeText(context, "Download succeeded", Toast.LENGTH_SHORT).show()
                } else if (status == DownloadManager.STATUS_FAILED) {
                    Toast.makeText(context, "Download failed", Toast.LENGTH_SHORT).show()
                }
            }
        } else if (DownloadManager.ACTION_NOTIFICATION_CLICKED.equals(intent.action)) {
            Toast.makeText(context, "Notification clicked", Toast.LENGTH_SHORT).show()
        }
    }
}