다른 클래스에서도 계속 recyclerview 사용했었고 잘 실행됐었는데 이 클래스에서만 textview가 널값이 뜨네요,, 해결가능하신분 계실까요? 실행시킬 때는 오류 없었습니다.

혹시 몰라 전체코드도 붙입니다..

<my_free_board_list_two.xml>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.recyclerview.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/my_free_board_recylcerview"/>



</LinearLayout>

item_article_two.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/writer_profile"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_margin="10dp" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <TextView
            android:id="@+id/writer_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="글쓴이" />

        <TextView
            android:id="@+id/writer_title"
            android:text="제목"
            android:layout_marginTop="10dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/writer_time"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="작성시간"
            android:layout_marginTop="10dp"/>

    </LinearLayout>
    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="#000000" />
</LinearLayout>

My_Free_Board_List_two.class

public class My_Free_Board_List_two extends AppCompatActivity {

    private RecyclerView recyclerView;


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

        recyclerView = (RecyclerView) findViewById(R.id.my_free_board_recylcerview);


        getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);

        recyclerView.setLayoutManager(new LinearLayoutManager(My_Free_Board_List_two.this));
        recyclerView.setAdapter(new My_Free_Board_List_two.RecyclerViewAdapter());


    }

    class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        List<Article_Model> articles;

        public  RecyclerViewAdapter() {

            articles = new ArrayList<>();

            FirebaseDatabase.getInstance().getReference().child("Free_Board").addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull @NotNull DataSnapshot snapshot) {
                    for(DataSnapshot item : snapshot.getChildren()){
                        articles.add(item.getValue(Article_Model.class));
                    }
                    notifyDataSetChanged();

                    recyclerView.scrollToPosition(articles.size() -1 );
                }

                @Override
                public void onCancelled(@NonNull @NotNull DatabaseError error) {

                }
            });

        }


        @NonNull
        @NotNull
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull @NotNull ViewGroup parent, int viewType) {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_article_two,parent,false);

            return new BoardViewHolder(view);

        }

        @Override
        public void onBindViewHolder(@NonNull @NotNull RecyclerView.ViewHolder holder, int position) {

            BoardViewHolder boardViewHolder = ((BoardViewHolder)holder);

            System.out.println(articles.get(position).nickname);

            Log.d("park", articles.get(position).nickname);

            boardViewHolder.writer_name.setText(articles.get(position).nickname);

            boardViewHolder.writer_title.setText(articles.get(position).title);
            boardViewHolder.writer_time.setText(articles.get(position).writing_time);

            Glide.with(holder.itemView.getContext())
                    .load(articles.get(position).imageUri)
                    .apply(new RequestOptions().circleCrop())
                    .into(boardViewHolder.writer_profile);



        }

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

        private class BoardViewHolder extends RecyclerView.ViewHolder {

            public TextView writer_name;
            public TextView writer_title;
            public TextView writer_time;
            public ImageView writer_profile;


            public BoardViewHolder(View view) {
                super(view);

                writer_name = (TextView)findViewById(R.id.writer_name);
                writer_title = (TextView)findViewById(R.id.writer_title);
                writer_time = (TextView)findViewById(R.id.writer_time);
                writer_profile = (ImageView)findViewById(R.id.writer_profile);
            }
        }
    }
}