fragment에서 Volley를 사용해서 Json을 RecyclerView 뿌리려는데 에러가 발생합니다.

Question

혼자 책의 예제를 엑티비티 방식에서 프레그먼트 방식으로 변경해서 테스트를 해보려는데 계속 

에러가 발생해서 질문을 드립니다. 아래는 소스 내용입니다.

package com.example.test;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.google.gson.Gson;

import java.util.HashMap;
import java.util.Map;

public class Fragment2 extends Fragment {
    RequestQueue requestQueue;
    RecyclerView recyclerView;
    MovieAdapter adapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment2, container, false);

        makeRequest(rootView);

        if (requestQueue == null) {
            requestQueue = Volley.newRequestQueue(getActivity());
        }

        recyclerView = (RecyclerView)rootView.findViewById(R.id.recyclerView);
        LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());

        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setAdapter(adapter);

        return rootView;
    }

    private  void makeRequest(View rootView) {
        String url = "http://www.kobis.or.kr/kobisopenapi/webservice/rest/boxoffice/searchDailyBoxOfficeList.json?key=24258683e583fa09cb007d36fd084860&targetDt=20191101";

        StringRequest request = new StringRequest(
                Request.Method.GET,
                url,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        println("응답 -> " + response);
                        processResponse(response);
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        println("에러 -> " + error.getMessage());
                    }
                }
        ) {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String,String> params = new HashMap<String,String>();
                return params;
            }
        };
        request.setShouldCache(false);
        requestQueue.add(request);
        println("요청 보냄.");
    }

    public void println(String data) {
        Log.d("Fragment", data);
    }

    public void processResponse(String response) {
        Gson gson = new Gson();
        MovieList movieList = gson.fromJson(response, MovieList.class);

        println("영화정보의 수 : " + movieList.boxOfficeResult.dailyBoxOfficeList.size());

        for (int i = 0; i < movieList.boxOfficeResult.dailyBoxOfficeList.size(); i++) {
            Movie movie = movieList.boxOfficeResult.dailyBoxOfficeList.get(i);

            adapter.addItem(movie);
        }

        adapter.notifyDataSetChanged();
    }

}

 

아래의 부분에서 계속 에러가 발생을 하는데 이유를 잘 모르겠네요..

makeRequest(rootView);

 requestQueue.add(request);

 

아래는 에러 코드입니다.

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.test, PID: 4675
    java.lang.NullPointerException: Attempt to invoke virtual method 'com.android.volley.Request com.android.volley.RequestQueue.add(com.android.volley.Request)' on a null object reference
        at com.example.test.Fragment2.makeRequest(Fragment2.java:75)
        at com.example.test.Fragment2.onCreateView(Fragment2.java:33)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
        at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
        at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
        at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
        at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
        at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273)
        at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:733)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)