androidserviceandroid-asynctasknullpointerexception

Asynctask in service with an 'onPostExecute' error

Consider:

Error : NullPointerException
        can't get data in onPostExecute();

I create an AsyncTask in onStartCommand() of a Service;

After startService:

  1. LoadDataFromNetwork.getData runs in doInBackground. This method will get data from the Internet. It can be work, and I can see the Log;

  2. I can't get data in onPostExcute();

    Why?

  3. Error image

    Enter image description here

  4. Code:

     public class Service_LoadAndStoreData extends Service {

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

     @Override
     public int onStartCommand(Intent intent, int flags, int startId) {

         Log.d(Application.TAG , "service start");
         new AsyncTask<Void ,Void ,List<ChannelBeans>>(){
             @Override
             protected List<ChannelBeans> doInBackground(Void... params) {
                 return LoadDataFromNetwork.getData();//it can be work
             }

             @Override
             protected void onPostExecute(List<ChannelBeans> channelBeanses) {
                 super.onPostExecute(channelBeanses);
                 Log.d(Application.TAG , channelBeanses.toString()); //Error :NullPointerException;
             }
         }.execute();

         return super.onStartCommand(intent, flags, startId);
     }

     @Override
     public IBinder onBind(Intent intent) {
         return null;
     }
 }
Solution

  • The problem is at the getData() method from LoadDataFromNetwork class, I think.