它不是读取文件夹中的唱片封面，而是读取播放列表的封面

private ArrayList<String> folderNames;
static ArrayList<MusicFiles> musicFiles;
private Context mContext;

public FolderAdapter(ArrayList<String> folderNames, ArrayList<MusicFiles> musicFiles, Context mContext) {
    this.folderNames = folderNames;
    this.musicFiles = musicFiles;
    this.mContext = mContext;
}
@NonNull
@Override
public MyHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
   View view = LayoutInflater.from(mContext).inflate(R.layout.folder_item, parent,
           false);
    return new MyHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyHolder holder,  final int position) {
    int index = folderNames.get(position).lastIndexOf("/");
    String folder = folderNames.get(position).substring(index + 1);
    holder.folder.setText(folder);
    holder.counterFiles.setText(String.valueOf(NumberOffFiles(folderNames.get(position))));
    Bitmap image = getAlbum(musicFiles.get(position).getPatch());
    if (image != null) {
        Glide.with(mContext).asBitmap()
                .load(image)
                .into(holder.cover);
    } else {
        Glide.with(mContext)
                .load(R.drawable.img_music)
                .into(holder.cover);
    }
    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(mContext,VideoFolderActivity.class);
            intent.putExtra("folderNames", folderNames.get(position));
            mContext.startActivity(intent);
        }
    });
}
@Override
public int getItemCount() {
    return folderNames.size();
}

static class MyHolder extends RecyclerView.ViewHolder {
    TextView folder, counterFiles;
    ImageView capa_da_pasta;
    public MyHolder(@NonNull View itemView) {
        super(itemView);
        folder = itemView.findViewById(R.id.folderName);
        counterFiles = itemView.findViewById(R.id.count_files_folder);
        cover = itemView.findViewById(R.id.folderImage);
    }
}
int NumberOffFiles(String folderNames){
    int countFiles = 0;
    for (MusicFiles musicFiles : musicFiles) {
        if (musicFiles.getPatch()
                .substring(0, musicFiles.getPatch().lastIndexOf("/"))
        .endsWith(folderNames)) {
            countFiles++;
        }
    }
    return countFiles;
}

代码必须阅读专辑封面！！！
代码必须阅读专辑封面！！！
它不是读取文件夹中的唱片封面，而是读取播放列表的封面