title: 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference when notify notification Android
body: <p>so, I was trying to run my app and it should be show the notification after the first run. But then, it gave me an error like this:</p>
  
  <pre><code>java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.app.Notification$Builder.&lt;init&gt;(Notification.java:1951)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompatApi21$Builder.&lt;init&gt;(NotificationCompatApi21.java:68)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompat$NotificationCompatImplApi21.build(NotificationCompat.java:759)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.support.v4.app.NotificationCompat$Builder.build(NotificationCompat.java:1559)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu.createButtonNotification(MainMenu.java:383)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu$DataBinatangOperation.onPostExecute(MainMenu.java:235)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at apps.skripsi.petvac.navigationmenu.MainMenu$DataBinatangOperation.onPostExecute(MainMenu.java:145)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask.finish(AsyncTask.java:632)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask.access$600(AsyncTask.java:177)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.Handler.dispatchMessage(Handler.java:102)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.os.Looper.loop(Looper.java:135)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at android.app.ActivityThread.main(ActivityThread.java:5253)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Native Method)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at java.lang.reflect.Method.invoke(Method.java:372)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
  12-10 12:01:03.512 3132-3132/apps.skripsi.petvac E/AndroidRuntime:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
  </code></pre>
  
  <p>and here's my full code</p>
  
  <pre><code>package apps.skripsi.petvac.navigationmenu;
  
  
  import android.app.Activity;
  import android.app.NotificationManager;
  import android.app.PendingIntent;
  import android.app.ProgressDialog;
  import android.content.Context;
  import android.content.Intent;
  import android.media.RingtoneManager;
  import android.net.Uri;
  import android.os.AsyncTask;
  import android.os.Bundle;
  import android.support.annotation.Nullable;
  import android.support.design.widget.FloatingActionButton;
  import android.support.v4.app.Fragment;
  import android.support.v4.app.NotificationCompat;
  import android.support.v4.app.TaskStackBuilder;
  import android.support.v4.widget.SwipeRefreshLayout;
  import android.util.Log;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.AdapterView;
  import android.widget.ImageView;
  import android.widget.ListView;
  import android.widget.TextView;
  import android.widget.Toast;
  
  import org.apache.http.client.ClientProtocolException;
  import org.joda.time.DateTime;
  import org.joda.time.Days;
  import org.json.JSONArray;
  import org.json.JSONException;
  import org.json.JSONObject;
  
  import java.io.IOException;
  import java.text.DateFormat;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Locale;
  
  import apps.skripsi.petvac.MainMenu.MainMenuAdapter;
  import apps.skripsi.petvac.R;
  import apps.skripsi.petvac.addpetdata.MainAddPetDataActivity;
  import apps.skripsi.petvac.Services.NotificationHandler;
  import apps.skripsi.petvac.notification.NotificationButtonReceiver;
  import apps.skripsi.petvac.notification.TestActivity;
  import apps.skripsi.petvac.parser.JSONParser;
  import apps.skripsi.petvac.petinformation.MainPetInformation;
  import apps.skripsi.petvac.preference.PreferencesHelper;
  
  /**
   * Created by widi on 9/9/2015.
   */
  public class MainMenu extends Fragment {
  
      FloatingActionButton FAB;
      JSONObject json;
      JSONObject jsonObject;
      PreferencesHelper pref;
      ProgressDialog loading;
      NotificationHandler NH;
      ImageView iv;
      ProgressDialog progress;
      NotificationManager mNotificationManager;
      SwipeRefreshLayout mSwipeRefreshLayout = null;
      ListView list;
      TextView tv;
      String result;
      String sisaWaktu;
      String ID_USER, ID_BINATANG, NAMA_BINATANG, JENIS_BINATANG, FOTO_BINATANG, RAS_BINATANG, TANGGAL_VAKSIN, NAMA_VAKSIN, ID_DATA_WAKTU_VAKSINASI;
  
      ArrayList&lt;HashMap&lt;String, String&gt;&gt; listBinatang = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;();
  
      public static String id_user = "id_user";
      public static String id_binatang = "id_binatang";
      public static String nama_binatang = "nama_binatang";
      public static String jenis_binatang = "jenis_binatang";
      public static String foto_binatang = "foto_binatang";
      public static String ras_binatang = "ras_binatang";
      public static String tanggal_vaksin = "tanggal_awal";
      public static String nama_vaksin = "nama_vaksin";
      public static String id_data_waktu_vaksinasi = "id_data_waktu_vaksinasi";
  
      private Context context;
  
      private static String url = "http://petvaccination.hol.es/api/data_menu_utama_vaksinasi.php";
  
      private static String urlgambar = "http://petvaccination.hol.es/imgupload/uploadedimages/";
  
      public MainMenu() {
      }
  
      @Nullable
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
          View v = inflater.inflate(R.layout.main_menu_fragment, container, false);
  
          FAB = (FloatingActionButton) v.findViewById(R.id.buttonTambahData);
  
          mSwipeRefreshLayout = (SwipeRefreshLayout) v.findViewById(R.id.activity_main_swipe_refresh_layout);
  
  
  
  
          pref = new PreferencesHelper(getActivity().getBaseContext());
  
          tv = (TextView) v.findViewById(R.id.textView);
  
          list = (ListView) v.findViewById(R.id.list_hewan);
  
          NH = NotificationHandler.getInstance(getActivity());
  
          FAB.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  Intent a = new Intent(getActivity(), MainAddPetDataActivity.class);
                  startActivity(a);
              }
          });
  
  
          new DataBinatangOperation().execute(url);
  
          mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
              @Override
              public void onRefresh() {
                  new DataBinatangOperation().execute(url);
                  updateList();
              }
          });
  
  
          return v;
      }
  
      private void updateList() {
  
          if (mSwipeRefreshLayout.isRefreshing()) {
              mSwipeRefreshLayout.setRefreshing(false);
          }
      }
  
  
      private class DataBinatangOperation extends AsyncTask&lt;String, Void, String&gt; {
  
          MainMenuAdapter adapter = new MainMenuAdapter(MainMenu.this,
                  listBinatang);
  
          @Override
          protected String doInBackground(String... params) {
  
              JSONArray json;
              try {
                  result = JSONParser.getPage(url);
              } catch (ClientProtocolException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              } catch (IOException e) {
                  // TODO Auto-generated catch block
                  e.printStackTrace();
              }
  
  
              return result;
          }
  
  
          @Override
          protected void onPostExecute(String result) {
  
              //updateList();
              tv.setVisibility(View.GONE);
  
              //mSwipeRefreshLayout.setRefreshing(false);
  
  
              try {
                  System.out.print("result = " + result);
                  json = new JSONObject(result);
                  progress.dismiss();
  
                  JSONArray objek = json.getJSONArray("data_vaksinasi_menu");
  
                  for (int i = 0; i &lt; objek.length(); i++) {
  
                      JSONObject jo = objek.getJSONObject(i);
  
                      ID_USER = jo.getString(id_user);
                      ID_BINATANG = jo.getString(id_binatang);
                      NAMA_BINATANG = jo.getString(nama_binatang);
                      JENIS_BINATANG = jo.getString(jenis_binatang);
                      FOTO_BINATANG = jo.getString(foto_binatang);
                      RAS_BINATANG = jo.getString(ras_binatang);
                      ID_DATA_WAKTU_VAKSINASI = jo.getString(id_data_waktu_vaksinasi);
                      TANGGAL_VAKSIN = jo.getString(tanggal_vaksin);
                      NAMA_VAKSIN = jo.getString(nama_vaksin);
                      if (pref.getPreferences("ID").equals(ID_USER)) {
  
                          if (jo.isNull(id_data_waktu_vaksinasi) &amp;&amp; jo.isNull(tanggal_vaksin)  &amp;&amp; jo.isNull(nama_vaksin)) {
                              NAMA_VAKSIN = "belum ada data";
                              sisaWaktu = "";
                          }else {
  
                              DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd", Locale.getDefault());
  
                              Calendar waktuSekarang = Calendar.getInstance();
  
                              Date date1 = waktuSekarang.getTime();
                              Date date2 = new Date();
  
                              date2 = formatter.parse(TANGGAL_VAKSIN);
  
  
                              if (date2.after(date1)) {
                                  int days = Days.daysBetween(new DateTime(date1), new DateTime(date2)).getDays();
                                  if (days &gt; 7 &amp;&amp; days &lt;= 30) {
                                      int weeks = days / 7;
                                      sisaWaktu = String.valueOf(weeks) + " minggu";
                                  } else if (days &gt; 30 &amp;&amp; days &lt;= 365) {
                                      int months = days / 30;
                                      sisaWaktu = String.valueOf(months) + " bulan";
                                  } else if (days &gt; 365) {
                                      int years = days / 365;
                                      sisaWaktu = String.valueOf(years) + " tahun";
                                  } else {
                                      sisaWaktu = String.valueOf(days) + " hari";
                                      if (days &lt;= 5) {
                                          createSimpleNotification(getActivity(), NAMA_BINATANG, sisaWaktu, ID_BINATANG);
                                      }
                                  }
                              } else if (date2.before(date1)) {
                                  int days = Days.daysBetween(new DateTime(date2), new DateTime(date1)).getDays();
                                  sisaWaktu = "lewat " + String.valueOf(days) + " hari";
                                  createButtonNotification(context, NAMA_BINATANG, sisaWaktu, ID_BINATANG, ID_DATA_WAKTU_VAKSINASI);
  
                              } else if (date2.equals(date1)) {
                                  sisaWaktu = "sekarang";
                                  createButtonNotification(context, NAMA_BINATANG, sisaWaktu, ID_BINATANG, ID_DATA_WAKTU_VAKSINASI);
                              }
  
                          }
  
                      }
  
                      HashMap&lt;String, String&gt; map = new HashMap&lt;String, String&gt;();
  
                      map.put(id_binatang, ID_BINATANG);
                      map.put(nama_binatang, NAMA_BINATANG);
                      map.put(jenis_binatang, JENIS_BINATANG);
                      map.put(foto_binatang, urlgambar + FOTO_BINATANG);
                      map.put(ras_binatang, RAS_BINATANG);
                      map.put(tanggal_vaksin, sisaWaktu);
                      map.put(nama_vaksin, NAMA_VAKSIN);
  
  
                      if (pref.getPreferences("ID").equals(ID_USER)) {
                          listBinatang.add(map);
                      }
  
  
                  }
  
                  if(String.valueOf(listBinatang).equals("[]")){
                      tv.setVisibility(View.VISIBLE);
                  }
  
                  System.out.println("hasil list : " + String.valueOf(listBinatang));
  
                  System.out.println("adapter : " + String.valueOf(adapter));
                  list.setAdapter(adapter);
  
  
  
                  /*list.setVisibility(View.VISIBLE);*/
                  list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
  
                      @Override
                      public void onItemClick(AdapterView&lt;?&gt; parent, View view,
                                              int position, long idx) {
  
                          HashMap&lt;String, String&gt; ambilid = new HashMap&lt;String, String&gt;();
                          ambilid = listBinatang.get(position);
  
                          Toast.makeText(getActivity(), "pindah halaman", Toast.LENGTH_SHORT).show();
  
                          Intent a = new Intent(getActivity(), MainPetInformation.class);
                          pref.savePreferences("IDB", ambilid.get(MainMenu.id_binatang));
                          pref.savePreferences("NAMAB", ambilid.get(MainMenu.nama_binatang));
                          pref.savePreferences("FOTOB", ambilid.get(MainMenu.foto_binatang));
                          pref.savePreferences("JENISB", ambilid.get(MainMenu.jenis_binatang));
                          pref.savePreferences("RASB", ambilid.get(MainMenu.ras_binatang));
                          startActivity(a);
                      }
  
                  });
  
              } catch (JSONException e1) {
                  // TODO Auto-generated catch block
                  e1.printStackTrace();
              } catch (ParseException e) {
                  e.printStackTrace();
              }
  
              // might want to change "executed" for the returned string passed
              // into onPostExecute() but that is upto you
          }
  
          @Override
          protected void onPreExecute() {
              listBinatang.clear();
              adapter.notifyDataSetChanged();
              progress = ProgressDialog.show(getActivity(), "Please Wait",
                      "Loading Data", true);
  
          }
  
          @Override
          protected void onProgressUpdate(Void... values) {
          }
      }
  
      public void createSimpleNotification(Context context, String title, String content, String id) {
          // Creates an explicit intent for an Activity
          Intent resultIntent = new Intent(context, MainPetInformation.class);
          resultIntent.putExtra("id", id);
          context.startActivity(resultIntent);
  
          mNotificationManager = (NotificationManager)context.getSystemService(getActivity().NOTIFICATION_SERVICE);
  
          int IntID = Integer.valueOf(id);
  
          Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
          // Creating a artifical activity stack for the notification activity
          TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
          stackBuilder.addParentStack(TestActivity.class);
          stackBuilder.addNextIntent(resultIntent);
  
          // Pending intent to the notification manager
          PendingIntent resultPending = PendingIntent.getActivity(context, IntID, resultIntent, 0);
  
  
          // Building the notification
          NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
                  .setSmallIcon(R.drawable.logo) // notification icon
                  .setContentTitle(title) // main title of the notification
                  .setContentText(content + " lagi")
                  .setSound(uri) // notification text
                  .setContentIntent(resultPending);// notification intent
  
  
          // mId allows you to update the notification later on.
          mNotificationManager.notify(IntID, mBuilder.build());
      }
  
      public void createButtonNotification(Context context, String title, String content, String idb, String idv) {
          // Prepare intent which is triggered if the  notification button is pressed
  
          Log.d("idb", idb);
          Intent intent = new Intent(getActivity(), MainPetInformation.class);
          intent.putExtra("IDBIN", idb);
          intent.putExtra("IDVAK", idv);
  
          mNotificationManager = (NotificationManager)context.getSystemService(getActivity().NOTIFICATION_SERVICE);
  
          Uri uri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
  
          int IntID = Integer.valueOf(idb);
  
          PendingIntent IntentAccept = PendingIntent.getActivity(getActivity(), IntID, intent, 0);
  
          PendingIntent IntentCancel = PendingIntent.getActivity(getActivity(), IntID, intent, 0);
  
  
          // Building the notifcation
          NotificationCompat.Builder nBuilder = new NotificationCompat.Builder(context)
                  .setSmallIcon(R.drawable.logo) // notification icon
                  .setContentTitle(title) // notification title
                  .setContentText(content)
                  .setSound(uri)// content text
                  .addAction(R.drawable.accept, "Accept", IntentAccept) // accept notification button
                  .addAction(R.drawable.cancel, "Cancel", IntentCancel); // cancel notification button
  
  
          mNotificationManager.notify(IntID, nBuilder.build());
  
  
      }
  
  
  }
  </code></pre>
  
  <p>the error stated it occured on this line:</p>
  
  <pre><code>mNotificationManager.notify(IntID, nBuilder.build());
  </code></pre>
  
  <p>please help:(</p>