java - 为什么 Volley 抛出 java.lang.NullPointerException

Question

我使用下面的代码来获取JSON数据(img, name)，一切正常，但我在Google Console中的ANRs & Crashes下得到了很多报告：

java.lang.NullPointerException: 
  at maa.app.Fragments.fragmentAnime$3.onSuccess (fragmentAnime.java:75)
  at maa.app.Fragments.fragmentAnime$6.a (fragmentAnime.java:52)
  at maa.app.Fragments.fragmentAnime$6.onResponse (fragmentAnime.java:2)
  at com.android.volley.request.StringRequest.c (StringRequest.java:4)
  at com.android.volley.request.StringRequest.a (StringRequest.java:2)
  at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run (ExecutorDelivery.java:30)
  at android.os.Handler.handleCallback (Handler.java:789)
  at android.os.Handler.dispatchMessage (Handler.java:98)
  at android.os.Looper.loop (Looper.java:164)
  at android.app.ActivityThread.main (ActivityThread.java:6942)
  at java.lang.reflect.Method.invoke (Method.java)
  at com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:327)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1374)

我的应用程序 ：

public class MApplication extends MultiDexApplication {
    public static RequestQueue requestQueue;
    @Override
    public void onCreate() {
        super.onCreate();
        requestQueue = Volley.newRequestQueue(getApplicationContext());
    }

片段：

 StringRequest stringRequest = new StringRequest(Request.Method.GET,
                    URL_DATA,
                    s -> {
                        List<Post> listItems = new ArrayList<>();
                        try {
                            JSONObject jsonObject = new JSONObject(s);
                            JSONArray array = jsonObject.getJSONArray("bgs");
                            for (int i = 0; i < array.length(); i++) {
                                JSONObject o = array.getJSONObject(i);
                                Post item = new Post(
                                        o.optString("img"),
                                        o.optString("name")
                                );
                                listItems.add(item);
                            }
                            callback.onSuccess(listItems);
                        } catch (JSONException e) {
                            slowInternetConnection();
                        }
                    },
                    callback::onError) {
            };
            if (getActivity() != null && isAdded()) {
                stringRequest.setShouldCache(false);
                requestQueue.getCache().clear();
                requestQueue.add(stringRequest);
            }

谁能帮我解决这个问题？

标签： javaandroidandroid-volley