Попытка создать android приложение с searchview, которое позволяет искать пользователя в базе данных firebase по его имени. Помощь будет оценена по достоинству.

Question

код для моего класса адаптера: publi c class friendsAd расширяет RecyclerView.Adapter реализует Filterable {

ArrayList<friendsGs> mfriendsGs = new ArrayList<friendsGs>();
ArrayList<friendsGs> exampleListFull = new ArrayList<friendsGs>();
private FirebaseDatabase mFirebaseDatabase;
private DatabaseReference mDatabaseRef;
private ChildEventListener mChildEvent;

public  friendsAd (){

    mFirebaseDatabase = FirebaseDatabase.getInstance();
    mDatabaseRef = mFirebaseDatabase.getReference().child("users");
    mChildEvent = new ChildEventListener() {
        @Override
        public void onChildAdded(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {
            friendsGs pp = dataSnapshot.getValue(friendsGs.class);
            pp.setUid(dataSnapshot.getKey());
            mfriendsGs.add(pp);
            notifyItemInserted( mfriendsGs.size() - 1);
        }

        @Override
        public void onChildChanged(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {

        }

        @Override
        public void onChildRemoved(@NonNull DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(@NonNull DataSnapshot dataSnapshot, @Nullable String s) {

        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    };
    mDatabaseRef.addChildEventListener(mChildEvent);
}

@NonNull
@Override
public friendsVh onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    Context context = parent.getContext();

    View itemView = LayoutInflater.from(context)
            .inflate(R.layout.friends, parent, false);

    return new friendsVh(itemView);
}

@Override
public void onBindViewHolder(@NonNull friendsVh holder, int position) {
    friendsGs post = mfriendsGs.get(position);


    holder.userName.setText(post.getFullName());
    holder.time.setText(post.getStatus());
    Picasso.get().load(post.getProfileImage()).into(holder.profileImage);

}

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

@Override
public Filter getFilter() {
    return exampleFilter;
}

private Filter exampleFilter = new Filter() {
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        List<friendsGs> filteredList = new ArrayList<>();

        if (constraint == null || constraint.length() == 0) {
            filteredList.addAll(exampleListFull);
        } else {
            String filterPattern = constraint.toString().toLowerCase().trim();

            for (friendsGs item : exampleListFull) {
                if (item.getFullName().toLowerCase().contains(filterPattern)) {
                    filteredList.add(item);
                }
            }
        }

        FilterResults results = new FilterResults();
        results.values = filteredList;

        return results;
    }

    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
      //  mfriendsGs.clear();
        mfriendsGs.addAll((List)  results.values);
        notifyDataSetChanged();
    }
};


public class friendsVh extends RecyclerView.ViewHolder  implements View.OnClickListener{
    TextView  time, userName;
    CircleImageView profileImage;
    ImageView postimage;


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




        time = itemView.findViewById(R.id.friend_status);
        userName = itemView.findViewById(R.id.friend_user_name);
        profileImage = itemView.findViewById(R.id.friend_profile_image);

        itemView.setOnClickListener(this);

    }

    @Override
    public void onClick(View v) {

        int position = getAdapterPosition();
        friendsGs discpostClick = mfriendsGs.get(position);
        Intent intent = new Intent(v.getContext(), Ffriends_activity.class);
        intent.putExtra("Clickable", discpostClick);
        v.getContext().startActivity(intent);

    }
}

}

---

это код для моего основного активность

publi c класс MainActivity расширяет AppCompatActivity {

SearchView searchView;
RecyclerView recyclerView2;
friendsAd friendsAd;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    searchView =findViewById(R.id.search_view);


    friendsAd adapter3 = new friendsAd();
    recyclerView2 = findViewById(R.id.friends_result);
    recyclerView2.setHasFixedSize(true);
    LinearLayoutManager linearLayoutManager3 = new LinearLayoutManager(this);
    linearLayoutManager3.setReverseLayout(true);
    linearLayoutManager3.setStackFromEnd(true);
    recyclerView2.setLayoutManager(linearLayoutManager3);
    recyclerView2.setAdapter(adapter3);



    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            return false;
        }

        @Override
        public boolean onQueryTextChange(String newText) {
            friendsAd.getFilter().filter(newText);
            return false;
        }
    });
}

}

---

всякий раз, когда я начинаю связывать в окне поиска, приложение вылетает, я пробовал методы например, Как добавить поисковый фильтр в RecyclerView из firebase duplicate