java.lang.NullPointerException ошибка при использовании диспетчера аварийных сигналов

Question

Эта ошибка java.lang.NullPointerException отображается, когда я использую диспетчер аварийных сигналов для уведомления об ошибке с помощью приемника.

Я выбираю элемент от listView, затем он вызывает метод setNotification, после чего он устанавливает повторяющийся сигнал тревоги для уведомления о пожаре.

Это код:

public class TimesActivity extends OptionsMenu { 

    ArrayList<String> getTiName = new ArrayList<String>(); 
    ArrayList<String> getTiTime = new ArrayList<String>(); 
    ArrayList<String> getTiBroad = new ArrayList<String>(); 
    ArrayList<String> getTiImg = new ArrayList<String>(); 

    public DAOTimes timeDatabase = null; 
    int minutes; 
    String prNameSelected; 
    String prTimeSelected; 
    Long now, start; 
    int period; 
    AlarmManager am; 

    // ============================================================================= 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.listvideo); 
     timeDatabase = new DAOTimes(this); 
     getTimes(); 
     showTimes(); 
    }    

    // ============================================================================= 

    @Override 
    protected Dialog onCreateDialog(int id) { 

     switch (id) { 
     case 0: 
      // Create out AlterDialog 
      final CharSequence[] array = { "5 min", "10 min", "15 min", 
        "45 min", "60 min" }; 
      Builder builder = new AlertDialog.Builder(this); 

      builder.setCancelable(true); 

      builder.setNegativeButton("Cancel", 
        new DialogInterface.OnClickListener() { 
         public void onClick(DialogInterface dialog, 
           int whichButton) { 
         } 
        }); 
      builder.setSingleChoiceItems(array, -1, 
        new DialogInterface.OnClickListener() { 

         @Override 
         public void onClick(DialogInterface dialog, int which) { 
          // TODO Auto-generated method stub 
          if (array[which] == "1 min") { 
           minutes = 1; 
          } else if (array[which] == "10 min") { 
           minutes = 10; 
          } else if (array[which] == "15 min") { 
           minutes = 15; 
          } else if (array[which] == "45 min") { 
           minutes = 45; 
          } else if (array[which] == "60 min") { 
           minutes = 60; 
          } 

          dialog.dismiss(); 
         } 
        }); 
      AlertDialog dialog = builder.create(); 
      dialog.show(); 
     } 
     return super.onCreateDialog(id); 
    } 

    // ============================================================================= 

    public void setNotification() { 
     Toast.makeText(TimesActivity.this, "result : ", 
       Toast.LENGTH_LONG).show(); 
     Calendar calendar = Calendar.getInstance(); 
     calendar.setTimeInMillis(System.currentTimeMillis()); 
     calendar.add(Calendar.MILLISECOND, period); 

     Intent intent = new Intent(this, NotAlarm.class); 
     PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, 
       intent, PendingIntent.FLAG_CANCEL_CURRENT); 
     am.setRepeating(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), 
       30000, pendingIntent); 



    } 

    // ============================================================================= 

    public void showTimes() { 
     final ListView listview = (ListView) findViewById(R.id.listView1); 

     listview.setOnItemClickListener(new ListView.OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View v, 
        int position, long id) {     

       prNameSelected = getTiName.get(position); 
       prTimeSelected = getTiTime.get(position); 
       String date = getIntent().getStringExtra("DAY_DATE"); 

       SimpleDateFormat format = new SimpleDateFormat(
         "yyyy-MM-dd, HH:mm:ss.SS"); 
       format.setLenient(false); 

       Calendar calendar = Calendar.getInstance(); 
       int year = calendar.get(Calendar.YEAR); 
       int month = calendar.get(Calendar.MONTH); 
       int day = calendar.get(Calendar.DAY_OF_MONTH); 
       int hour = calendar.get(Calendar.HOUR_OF_DAY); 
       int minute = calendar.get(Calendar.MINUTE); 
       int second = calendar.get(Calendar.SECOND); 
       int millisecond = calendar.get(Calendar.MILLISECOND); 

       String time1 = year + "-" + (month + 1) + "-" + day + ", " 
         + hour + ":" + minute + ":" + second + "." 
         + millisecond; 
       Date date1; 
       try { 
        date1 = format.parse(time1); 
        now = date1.getTime(); 
       } catch (ParseException e) {      
        e.printStackTrace(); 
       } 

       String time2 = date + ", " + prTimeSelected + ":00.00"; 
       Date date2; 
       try { 
        date2 = format.parse(time2); 
        start = date2.getTime(); 
       } catch (ParseException e) {      
        e.printStackTrace(); 
       } 

       int result = (int) (start - now); 

       if (start > now) { 
        period = result; 
       } else { 
        // period = start + (7 * 24 * 60 * 60 * 1000); 
       }    

       Toast.makeText(TimesActivity.this, "result : " + period, 
         Toast.LENGTH_LONG).show(); 
       setNotification(); 
//    showDialog(0); 
      } 
     }); 

     listview.setAdapter(new TimesAdapter(TimesActivity.this, getTiName 
       .toArray(new String[getTiName.size()]), getTiTime 
       .toArray(new String[getTiTime.size()]), getTiBroad 
       .toArray(new String[getTiBroad.size()]), getTiImg 
       .toArray(new String[getTiImg.size()]))); 
    } 
} 

Receiver активность:

package com.shadatv.shada; 

import android.app.Notification; 
import android.app.NotificationManager; 
import android.app.PendingIntent; 
import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 

public class NotAlarm extends BroadcastReceiver { 

    NotificationManager nm; 

    @Override 
    public void onReceive(Context context, Intent intent) { 
     // TODO Auto-generated method stub 

     NotificationManager nm = (NotificationManager) context 
       .getSystemService(Context.NOTIFICATION_SERVICE); 

     Notification.Builder builder = new Notification.Builder(context); 
     builder.setSmallIcon(android.R.drawable.btn_star); 
     builder.setTicker("notification"); 

     Notification notify = builder.getNotification(); 

     CharSequence title = "you have been notified"; 
     CharSequence details = "bvcburhvurh uhuh hghu hu"; 

     PendingIntent pending = PendingIntent 
       .getActivity(context, 0, new Intent(), 0); 
     notify.setLatestEventInfo(context, title, details, pending); 

     nm.notify(0, notify); 

    } 

} 

LogCat:

03-27 10:39:33.550: E/AndroidRuntime(3890): FATAL EXCEPTION: main 
03-27 10:39:33.550: E/AndroidRuntime(3890): java.lang.NullPointerException 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at com.shadatv.shada.TimesActivity.setNotification(TimesActivity.java:161) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at com.shadatv.shada.TimesActivity$3.onItemClick(TimesActivity.java:228) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.widget.AdapterView.performItemClick(AdapterView.java:292) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.widget.AbsListView.performItemClick(AbsListView.java:1179) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.widget.AbsListView$PerformClick.run(AbsListView.java:2707) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.widget.AbsListView$1.run(AbsListView.java:3462) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.os.Handler.handleCallback(Handler.java:605) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.os.Handler.dispatchMessage(Handler.java:92) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.os.Looper.loop(Looper.java:137) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at android.app.ActivityThread.main(ActivityThread.java:4507) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at java.lang.reflect.Method.invoke(Method.java:511) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 
03-27 10:39:33.550: E/AndroidRuntime(3890):  at dalvik.system.NativeStart.main(Native Method) 

Answer 1

Вы забыли инициализировать диспетчер am сигнализации.

Инициализировать его следующим образом.

AlarmManager am = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);