Adapter

public class RankAdapter extends RecyclerView.Adapter<RankAdapter.MyViewAdapter> {

    private Context context;
    private List<User> userData;

    public RankAdapter(Context context, List<User> userData) {
        this.context = context;
        this.userData = userData;
    }

    @NonNull
    @Override
    public MyViewAdapter onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        return new MyViewAdapter(LayoutInflater.from(context).inflate(R.layout.rank_row_item, parent, false));
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewAdapter holder, int position) {

        holder.textViewUserName.setText(userData.get(position).getUserName());
        holder.textViewLevel.setText("Completado: " + userData.get(position).getLevel() + "%");

    }

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

    public class MyViewAdapter extends RecyclerView.ViewHolder{

        private TextView textViewUserName, textViewLevel;

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

            textViewUserName = itemView.findViewById(R.id.itemName);
            textViewLevel = itemView.findViewById(R.id.itemLevel);

        }
    }
}