temp.java

class MainActivity : AppCompatActivity(), CacheDataSource.EventListener, TransferListener {

    private var player: SimpleExoPlayer? = null

    companion object {
        // About 10 seconds and 1 meg.
//        const val VIDEO_URL = "https://sample-videos.com/video123/mp4/720/big_buck_bunny_720p_1mb.mp4"

        // About 1 minute and 5.3 megs
        const val VIDEO_URL = "http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4"

        // The full movie about 355 megs.
//        const val VIDEO_URL = "http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_60fps_normal.mp4"

        // Use to download video other than the one you are viewing. See #3 test of the answer.
//        const val VIDEO_URL_LIE = "http://file-examples.com/wp-content/uploads/2017/04/file_example_MP4_480_1_5MG.mp4"

        // No changes in code deleted here.

    //NOTE: I know I shouldn't use an AsyncTask. It's just a sample...
    @SuppressLint("StaticFieldLeak")
    fun tryShareCacheFile() {
        // file is cached and ready to be used
        object : AsyncTask<Void?, Void?, File>() {
            override fun doInBackground(vararg params: Void?): File {
                val tempFile = FilesPaths.FILE_TO_SHARE.getFile(this@MainActivity, true)
                getCachedData(this@MainActivity, cache, VIDEO_URL, tempFile)
                return tempFile
            }

            override fun onPostExecute(result: File) {
                super.onPostExecute(result)
                val intent = prepareIntentForSharingFile(this@MainActivity, result)
                startActivity(intent)
            }
        }.execute()
    }

    private var mTotalBytesToRead = 0L
    private var mBytesReadFromCache: Long = 0
    private var mBytesReadFromNetwork: Long = 0

    @WorkerThread
    fun getCachedData(
        context: Context, myCache: Cache?, url: String, tempfile: File
    ): Boolean {
        var isSuccessful = false
        val myUpstreamDataSource = DefaultHttpDataSourceFactory(ExoPlayerEx.getUserAgent(context)).createDataSource()
        val dataSource = CacheDataSource(
            myCache,
            // If the cache doesn't have the whole content, the missing data will be read from upstream
            myUpstreamDataSource,
            FileDataSource(),
            // Set this to null if you don't want the downloaded data from upstream to be written to cache
            CacheDataSink(myCache, CacheDataSink.DEFAULT_BUFFER_SIZE.toLong()),
            /* flags= */ 0,
            /* eventListener= */ this
        )

        // Listen to the progress of the reads from cache and the network.
        dataSource.addTransferListener(this)

        var outFile: FileOutputStream? = null
        var bytesRead = 0

        // Total bytes read is the sum of these two variables.
        mTotalBytesToRead = C.LENGTH_UNSET.toLong()
        mBytesReadFromCache = 0
        mBytesReadFromNetwork = 0

        try {
            outFile = FileOutputStream(tempfile)
            mTotalBytesToRead = dataSource.open(DataSpec(Uri.parse(url)))
            // Just read from the data source and write to the file.
            val data = ByteArray(1024)

            Log.d("getCachedData", "<<<<Starting fetch...")
            while (bytesRead != C.RESULT_END_OF_INPUT) {
                bytesRead = dataSource.read(data, 0, data.size)
                if (bytesRead != C.RESULT_END_OF_INPUT) {
                    outFile.write(data, 0, bytesRead)
                }
            }
            isSuccessful = true
        } catch (e: IOException) {
            // error processing
        } finally {
            dataSource.close()
            outFile?.flush()
            outFile?.close()
        }

        return isSuccessful
    }

    override fun onCachedBytesRead(cacheSizeBytes: Long, cachedBytesRead: Long) {
        Log.d("onCachedBytesRead", "<<<<Cache read? Yes, (byte read) $cachedBytesRead (cache size) $cacheSizeBytes")
    }

    override fun onCacheIgnored(reason: Int) {
        Log.d("onCacheIgnored", "<<<<Cache ignored. Reason = $reason")
    }

    override fun onTransferInitializing(source: DataSource?, dataSpec: DataSpec?, isNetwork: Boolean) {
        Log.d("TransferListener", "<<<<Initializing isNetwork=$isNetwork")
    }

    override fun onTransferStart(source: DataSource?, dataSpec: DataSpec?, isNetwork: Boolean) {
        Log.d("TransferListener", "<<<<Transfer is starting isNetwork=$isNetwork")
    }

    override fun onTransferEnd(source: DataSource?, dataSpec: DataSpec?, isNetwork: Boolean) {
        reportProgress(0, isNetwork)
        Log.d("TransferListener", "<<<<Transfer has ended isNetwork=$isNetwork")
    }

    override fun onBytesTransferred(
        source: DataSource?,
        dataSpec: DataSpec?,
        isNetwork: Boolean,
        bytesTransferred: Int
    ) {
        // Report progress here.
        if (isNetwork) {
            mBytesReadFromNetwork += bytesTransferred
        } else {
            mBytesReadFromCache += bytesTransferred
        }

        reportProgress(bytesTransferred, isNetwork)
    }

    private fun reportProgress(bytesTransferred: Int, isNetwork: Boolean) {
        val percentComplete =
            100 * (mBytesReadFromNetwork + mBytesReadFromCache).toFloat() / mTotalBytesToRead
        val completed = "%.1f".format(percentComplete)
        Log.d(
            "TransferListener", "<<<<Bytes transferred: $bytesTransferred isNetwork=$isNetwork" +
                    " $completed% completed"
        )
    }

    // No changes below here.
}