E / ExoPlayerImplInternal：源错误-java.io.FileNotFoundException：subtitle.srt：打开失败：ENOENT（没有这样的文件或目录）？

Question

我已经集成了ExoPlayer，我写了一种在其中播放字幕的方法，但是ExoPlayer抛出此错误而不是加载，所以需要帮助！

我的想法：用户可以从网上下载字幕（.srt格式），当他们单击我编写的“ imgSubtitle”图像按钮时，它应该打开用户的存储空间，从中可以选择字幕文件，然后加载并在ExoPlayer中显示。

错误日志：

E/ExoPlayerImplInternal: Source error.
    com.google.android.exoplayer2.upstream.FileDataSource$FileDataSourceException: java.io.FileNotFoundException: /root/storage/emulated/0/Download/subtitle.srt: open failed: ENOENT (No such file or directory)
        at com.google.android.exoplayer2.upstream.FileDataSource.open(FileDataSource.java:70)
        at com.google.android.exoplayer2.upstream.DefaultDataSource.open(DefaultDataSource.java:147)
        at com.google.android.exoplayer2.source.SingleSampleMediaPeriod$SourceLoadable.load(SingleSampleMediaPeriod.java:355)
        at com.google.android.exoplayer2.upstream.Loader$LoadTask.run(Loader.java:308)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:919)
     Caused by: java.io.FileNotFoundException: /root/storage/emulated/0/Download/subtitle.srt: open failed: ENOENT (No such file or directory)
        at libcore.io.IoBridge.open(IoBridge.java:496)
        at java.io.RandomAccessFile.<init>(RandomAccessFile.java:289)
        at java.io.RandomAccessFile.<init>(RandomAccessFile.java:152)
        at com.google.android.exoplayer2.upstream.FileDataSource.open(FileDataSource.java:62)
        at com.google.android.exoplayer2.upstream.DefaultDataSource.open(DefaultDataSource.java:147) 
        at com.google.android.exoplayer2.source.SingleSampleMediaPeriod$SourceLoadable.load(SingleSampleMediaPeriod.java:355) 
        at com.google.android.exoplayer2.upstream.Loader$LoadTask.run(Loader.java:308) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:919) 
     Caused by: android.system.ErrnoException: open failed: ENOENT (No such file or directory)
        at libcore.io.Linux.open(Native Method)
        at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
        at libcore.io.BlockGuardOs.open(BlockGuardOs.java:252)
        at libcore.io.ForwardingOs.open(ForwardingOs.java:167)
        at android.app.ActivityThread$AndroidOs.open(ActivityThread.java:7581)
        at libcore.io.IoBridge.open(IoBridge.java:482)
        at java.io.RandomAccessFile.<init>(RandomAccessFile.java:289) 
        at java.io.RandomAccessFile.<init>(RandomAccessFile.java:152) 
        at com.google.android.exoplayer2.upstream.FileDataSource.open(FileDataSource.java:62) 
        at com.google.android.exoplayer2.upstream.DefaultDataSource.open(DefaultDataSource.java:147) 
        at com.google.android.exoplayer2.source.SingleSampleMediaPeriod$SourceLoadable.load(SingleSampleMediaPeriod.java:355) 
        at com.google.android.exoplayer2.upstream.Loader$LoadTask.run(Loader.java:308) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:919) 

我的代码：

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        imgSubtitle.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent fileintent = new Intent(Intent.ACTION_GET_CONTENT);
                fileintent.setType("gagt/sdf");
                try {
                    startActivityForResult(fileintent, PICKFILE_RESULT_CODE);
                } catch (ActivityNotFoundException e) {
                    Log.e("tag", "No activity can handle picking a file. Showing alternatives.");
                }
            }
        });
 }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Fix no activity available
        super.onActivityResult(requestCode, resultCode, data);
        if (data == null)
            return;
        switch (requestCode) {
            case PICKFILE_RESULT_CODE:
                if (resultCode == RESULT_OK) {
                    String FilePath = data.getData().getPath();

                    setSubSelectedSubtitle(mediaSource, FilePath, this);
                    //FilePath is your file as a string
                }
        }
    }

    public void setSubSelectedSubtitle(MediaSource mediaSource, String FilePath, Context context) {
        MergingMediaSource mergedSource;
        if (FilePath != null) {
            Uri subtitleUri = Uri.parse(FilePath);

            Format subtitleFormat = Format.createTextSampleFormat(
                    null, // An identifier for the track. May be null.
                    MimeTypes.TEXT_VTT, // The mime type. Must be set correctly.
                    Format.NO_VALUE, // Selection flags for the track.
                    "en"); // The subtitle language. May be null.

            DefaultDataSourceFactory dataSourceFactory = new DefaultDataSourceFactory(context,
                    Util.getUserAgent(context, getResources().getString(R.string.app_name)), new DefaultBandwidthMeter());


            MediaSource subtitleSource = new SingleSampleMediaSource
                    .Factory(dataSourceFactory)
                    .createMediaSource(subtitleUri, subtitleFormat, C.TIME_UNSET);


            mergedSource = new MergingMediaSource(mediaSource, subtitleSource);
            player.prepare(mergedSource, false, false);
            //resumePlayer();

        } else {
            Toast.makeText(context, "there is no subtitle", Toast.LENGTH_SHORT).show();
        }
    }

感谢您的帮助，谢谢！