Question

我正在尝试使用自定义请求在我的应用中实现凌空，但我不断收到此错误，我无法修复。

这是错误

java.lang.NullPointerException: Attempt to invoke virtual method 'void co.app.al.app.volley.AppController.addToRequestQueue(com.android.volley.Request, java.lang.String)' on a null object reference

这是AppController.java

public class AppController extends Application {

    public static final String TAG = AppController.class.getSimpleName();

    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;
    LruBitmapCache mLruBitmapCache;

    private static AppController mInstance;

    @Override
    public void onCreate() {
        super.onCreate();
        mInstance = this;
    }

    public static synchronized AppController getInstance() {
        return mInstance;
    }

    public RequestQueue getRequestQueue() {
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }

        return mRequestQueue;
    }

    public ImageLoader getImageLoader() {
        getRequestQueue();
        if (mImageLoader == null) {
            getLruBitmapCache();
            mImageLoader = new ImageLoader(this.mRequestQueue, mLruBitmapCache);
        }

        return this.mImageLoader;
    }

    public LruBitmapCache getLruBitmapCache() {
        if (mLruBitmapCache == null)
            mLruBitmapCache = new LruBitmapCache();
        return this.mLruBitmapCache;
    }

    public <T> void addToRequestQueue(Request<T> req, String tag) {
        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
        getRequestQueue().add(req);
    }

    public <T> void addToRequestQueue(Request<T> req) {
        req.setTag(TAG);
        getRequestQueue().add(req);
    }

    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
}

这是自定义请求

CustomRequest jsObjRequest = new CustomRequest(Request.Method.POST,
                            jsonUrl,paramsLogin,
                            new Response.Listener<JSONObject>() {
                                @Override
                                public void onResponse(JSONObject response) {
                                    try {
                                        VolleyLog.v("Response:%n %s", response.toString(4));
                                        int code = response.getInt("code");
                                        String message = response.getString("message");





                                        if (code == 1) {
                                            //Success go to verify
                                            Toast.makeText(getActivity().getApplicationContext(),
                                                    message,
                                                    Toast.LENGTH_LONG).show();
                                            Log.v(TAG, String.valueOf(code));
                                            Log.v(TAG, message);
//asd
                                        } else if (code == 2){

                                            int newId = response.getInt("uid");
                                            String returnDeviceToken = response.getString("device_token");

                                            Toast.makeText(getActivity().getApplicationContext(),
                                                    message,
                                                    Toast.LENGTH_LONG).show();

                                            Log.v(TAG, String.valueOf(newId));


                                            //Create the new login credentials for the user and save them to the shared preferences
                                            session.createLoginSession(newId, returnDeviceToken);

                                            //Send the user to the home page
                                            String mainMessage = "home";
                                            ((IndexUserActionActivity)getActivity()).startMainActivity(mainMessage);



                                        }else{
                                            Toast.makeText(getActivity().getApplicationContext(),
                                                    "Network Error",
                                                    Toast.LENGTH_LONG).show();

                                        }
                                    } catch (JSONException e) {
                                        e.printStackTrace();
                                    }
                                }
                            }, new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            VolleyLog.e("Error: ", error.getMessage());
                        }
                    });

                    //requestQueue.add(jsObjRequest);

                    AppController.getInstance().addToRequestQueue(jsObjRequest, tag_json_obj);

奇怪的是，这个完全相同的代码在我正在制作的另一个应用程序上正常工作，所以我看不出什么是错误的

感谢您的帮助

Answer 1

检查您的Manifest.xml，并将以下行添加到应用程序标记下的Manifest文件中。

android:name="com.example.logintest.app.AppController"

不要忘记更改包名称（com.example.logintest）

自定义排球请求的NullPointerException

1 个答案: