I’m completely new to android (some basic self-taught only java experience in last year).
I wanted to make a simple app that would open a PDF/txt file and audio file with the same name simultanously, and I was following this guide https://www.youtube.com/watch?v=TQg98mQL2hs as it seemed to be the closest to what I wanted to achieve.

But I got followin error:
Type ‘androidx.recyclerview.widget.RecyclerView.ViewHolder’ does not have type parameters

the class looks like this

package Etherfields.scripreader;

import android.content.Context;
import android.net.Uri;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;

public class RecyclerViewAdapter extends RecyclerView.ViewHolder<RecyclerViewAdapter> {
    private Context mContext;
    RecyclerViewAdapter(Context mContext) {
        this.mContext = mContext;
    }

    public RecyclerViewAdapter(@NonNull View itemView) {
        super(itemView);
    }

    @NonNull
    public FileLayoutHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.files_list, parent, false);

        return new FileLayoutHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerViewAdapter holder, int position) {
        ((FileLayoutHolder)holder).title.setText(Constant.allMediaList.get(position).getName());
        Uri uri = Uri.fromFile(Constant.allMediaList.get(position));

        Glide.with(mContext)
                .load(uri).thumbnail(O.lf).into(((FileLayoutHolder)holder).thumbnail);
    }

    @Override
    public int getItemCount() {
        return Constant.allMediaList.size();
    }

    class FileLayoutHolder extends RecyclerView.ViewHolder {

        ImageView thumbnail;
        TextView title;
        ImageButton ic_more_btn;

        public FileLayoutHolder (@NonNull View itemView) {
            super(itemView);

            thumbnail = itemView.findViewById(R.id.thumbnail);
            title = itemView.findViewById(R.id.title);
            ic_more_btn = itemView.findViewById(R.id.ic_more_btn);
        }
    }
}

please provide some really begginer level explanation I am only self-taught. (did not go to IT collage, did not take a course or bootcamp etc)

I’ve already tried to modify extends to:

RecyclerView.Adapter<RecyclerViewAdapter>
RecyclerView.ViewHolder<RecyclerView.ViewHolder>
RecyclerView.ViewHolder<RecyclerView.Adapter>

as well as rebuild everything hoping it was simply a cache issue