Android: Notification exception

Question

I'm trying to do my 1st notification and I'm getting an exception. On onCreate() method in main I call createNotification of SchedulerActivity class and in this procedure I call my BroadcastReceiver class. But I get an exception in SchedulerActivity when I'm calling BroadcastReceiver class on Intent myIntent = new Intent(SchedulerActivity.this, MyReceiver.class);, and I can't understand why.

Exception:

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.converter.android.daily/com.converter.android.daily.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ContextWrapper.getPackageName(ContextWrapper.java:133) at android.content.ComponentName.(ComponentName.java:128)
at android.content.Intent.(Intent.java:4449)
at com.converter.android.daily.SchedulerActivity.createNotification(SchedulerActivity.java:272) at com.converter.android.daily.MainActivity.onCreate(MainActivity.java:39) at android.app.Activity.performCreate(Activity.java:6251)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Main.class

public class MainActivity extends BaseActivity {
    private SchedulerActivity sch= new SchedulerActivity();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        sch.createNotification(this.getApplicationContext());
}

SchedulerActivity.class

public class SchedulerActivity extends Activity implements PickerFragment.OnCompleteListener {
(...)
public void createNotification(Context context){

        long when = System.currentTimeMillis();
        String []parts;
        String part1, part2;

        SharedPreferences pref = PreferenceManager.getDefaultSharedPreferences(context);
        status = pref.getString(botaoDaily, "");
        time   = pref.getString(dHora,"");

        if (status.compareToIgnoreCase("On")==0) {

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

            NotificationCompat.Builder mNotifyBuilder = new NotificationCompat.Builder(
                    context).setSmallIcon(R.drawable.ic_launcher)
                    .setContentTitle("Daily")
                    .setContentText("My first Notification")
                    .setAutoCancel(true).setWhen(when)
                    .setContentIntent(pendingIntent);
            // .setVibrate(new long[]{1000, 1000, 1000, 1000, 1000});
            notificationManager.notify(1, mNotifyBuilder.build());

            if(time.compareToIgnoreCase("")!=0) {

                parts = time.split(":");
                part1 = parts[0];
                part2 = parts[1];

                /*hours = Integer.valueOf(part1);
                minutes = Integer.valueOf(part2);
                seconds = 0;*/

                Calendar calendar = Calendar.getInstance();

                calendar.set(Calendar.HOUR_OF_DAY, 16);/*TODO: hours, minutes*/
                calendar.set(Calendar.MINUTE, 45);
                calendar.set(Calendar.SECOND, 15);

                //Service -> MyAlarmService
                Intent myIntent = new Intent(SchedulerActivity.this, MyReceiver.class);
                pendingIntent = PendingIntent.getBroadcast(SchedulerActivity.this, 0, myIntent, 0);
                AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);
                alarmManager.set(AlarmManager.RTC, calendar.getTimeInMillis(), pendingIntent);

                PendingIntent alarmIntent = PendingIntent.getBroadcast(context, 0, myIntent, 0);
                alarmManager.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 1000 /* milliseconds */ * 20 /* seconds */, alarmIntent);

            }
        }
    }

MyReceiver.class

public class MyReceiver extends BroadcastReceiver
{
   public void onReceive(Context context, Intent intent)
    {
      Intent service1 = new Intent(context, MyAlarmService.class);
        context.startService(service1);
    }
}

Can you please help me?

cylon cylon · Accepted Answer · 2015-12-19T16:44:06

private SchedulerActivity sch= new SchedulerActivity();

You can't instantiate activities, they can be instantiated only indirectly via intent creation. Try to refactor this activity to a simple class and pass context of the parent activity.

Android: Notification exception

2 Answers