在Android kotlin的内部存储中从Firebase读取和写入视频

Question

出于安全考虑，我想在高速缓存/内部存储器中保存和读取视频。在我的代码中，它第一次显示正在下载的视频，但之后没有视频播放，我什至无法从内部存储中读取视频。

它表明路径是目录而不是文件。

class VideoPlayer:AppCompatActivity() {

   lateinit var mfile2:File

    override fun onCreate(savedInstanceState: Bundle?) {


        super.onCreate(savedInstanceState)
        setContentView(R.layout.video_player)

        val model=intent.getStringExtra("object")
        Toast.makeText(this,model, Toast.LENGTH_SHORT).show()

        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE)

       val ProgressBar=findViewById<ProgressBar>(R.id.bufferProgress)

       // val options=findViewById<Button>(R.id.button2)
        button2.setOnClickListener(){
            startActivity(Intent(this,Options::class.java))
        }


        var contextWrapper: ContextWrapper = ContextWrapper(applicationContext)
        var directory: File = filesDir

        val mfile3= File(directory,"filename1.mp4")

        val videoUri=Uri.parse(mfile3.path)

        if(!mfile3.exists()){
            val videoUri=Uri.parse(model)
            videoView.setMediaController(MediaController(this))
            videoView.setVideoURI(videoUri)
            videoView.start()

            Log.d("in if condition","model of if conditon"+model)
            Log.d("in if condition","videoUri of if conditon"+videoUri)

        }
        else{
           val mydir = filesDir
val fileWithinMyDir = File(mydir, "filename1.mp4");
fileWithinMyDir.setReadable(true, false);
val videoResource = fileWithinMyDir.getPath();
val intentUri = Uri.fromFile( File(videoResource));
            videoView.setMediaController(MediaController(this))
            videoView.setVideoURI(intentUri)
            videoView.start()
            //Log.d("in else condition","model of if conditon"+model)
            Log.d("in else condition",fileWithinMyDir.isFile.toString())
            Log.d("in else conditino","checking path "+videoUri)
        }


        videoView.setOnPreparedListener { mediaPlayer ->
            mediaPlayer.setOnInfoListener(OnInfoListener { mp, what, extra ->
                if (what == MEDIA_INFO_BUFFERING_END) {
                    ProgressBar.visibility=View.INVISIBLE
                    return@OnInfoListener true
                } else if (what == MEDIA_INFO_BUFFERING_START) {
                    ProgressBar.visibility=View.VISIBLE
                }
                false
            })
            ProgressBar.visibility=View.INVISIBLE
            videoView.start()
        }



        videoView.setOnClickListener{
            Handler().postDelayed({
                val actionBar: ActionBar? = supportActionBar
                // window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_FULLSCREEN
                actionBar?.hide()
                window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_IMMERSIVE
                        // Set the content to appear under the system bars so that the
                        // content doesn't resize when the system bars hide and show.
                        or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                        // Hide the nav bar and status bar
                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                        or View.SYSTEM_UI_FLAG_FULLSCREEN)
            }, 1000)

        }
        val actionBar: ActionBar? = supportActionBar
        // window.decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_FULLSCREEN
        actionBar?.hide()



        window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_IMMERSIVE
                // Set the content to appear under the system bars so that the
                // content doesn't resize when the system bars hide and show.
                or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                // Hide the nav bar and status bar
                or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                or View.SYSTEM_UI_FLAG_FULLSCREEN)


        val completionListener =
            OnCompletionListener { mp ->
                mp.stop()
                startActivity(Intent(this,Options::class.java))
            }

        videoView.setOnCompletionListener(completionListener)


        btnDownload.setOnClickListener{
            downfile(model,"VideoDownload")
        }
    }

    fun downfile(urll:String,fileName:String) {


            var directory: File = filesDir

             mfile2= File(directory,"filename1.mp4")
           // mfile2.createNewFile();
        Log.d("dowloaded file","the path of downoaded file is "+mfile2.isFile)

            var downloadId = PRDownloader.download(urll, mfile2.absolutePath, fileName)
                .build()
                .setOnStartOrResumeListener(object : OnStartOrResumeListener {
                    override fun onStartOrResume() {
                        System.out.println("??????????????????? start")
                    }
                })
                .setOnPauseListener(object : OnPauseListener {
                    override fun onPause() {
                    }
                })
                .setOnCancelListener(object : OnCancelListener {
                    override fun onCancel() {
                    }
                })
                .setOnProgressListener(object : OnProgressListener {
                    override fun onProgress(progress: Progress) {

                        var per =
                            (progress.currentBytes.toFloat() / progress.totalBytes.toFloat()) * 100.00
                        System.out.println("::??????????????????? Per : " + per + " ?? : " + progress.currentBytes + " ?? : " + progress.totalBytes)

                      }
                })

                .start(object : OnDownloadListener {
                    override fun onDownloadComplete() {
                        System.out.println("??????????????????? complete")

                        Log.d("onDownloadListener","path of download file"+mfile2)
                    }

                    override fun onError(error: com.downloader.Error?) {
                        System.out.println("??????????????????? error"+error)  }


                })
            System.out.println("??????????????????? called")

        }
    }