NullPointerException in android: how to set context?

Question

How can I fix this error?

java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.hashCode()' on a null object reference
ACTIVITY.onNewIntent(Adult1Activity.java:243)

This is the method that includes this error:

private void ExtendedNotification(String time) {
    Intent resultIntent = new Intent(this, Adult1Activity.class);

    resultIntent.putExtra("A", "restore");
    PendingIntent restoreIntent = PendingIntent.getActivity(Adult1Activity.this, 0, resultIntent,
            PendingIntent.FLAG_UPDATE_CURRENT);

    resultIntent.putExtra("A", "close");
    PendingIntent closeIntent = PendingIntent.getActivity(Adult1Activity.this, 2, resultIntent,
            PendingIntent.FLAG_UPDATE_CURRENT);

     final NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(Adult1Activity.this)
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentTitle("App Name")
            .setContentText(time)
            .setAutoCancel(true)
            .addAction(new NotificationCompat.Action(R.mipmap.ic_launcher, "Restore", restoreIntent))
            .addAction(new NotificationCompat.Action(R.mipmap.ic_launcher, "Close", closeIntent))
            .setContentIntent(restoreIntent);

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

    Notification notification = notificationBuilder.build();
    notification.flags |= Notification.FLAG_NO_CLEAR | Notification.FLAG_ONGOING_EVENT;

    notificationManager.notify(0, notification);
}
@Override
protected void onNewIntent(Intent intent) {
    switch (intent.getStringExtra("A")) {
        case "restore":
            tv.setText(timeString);
            break;

        case "close":
            countDownTimer.cancel();
            isRunning = false;
            notificationManager.cancel(0);
            CloseApp();
            break;
    }

I think the problem is not using context in it.

There is a Counter with StopBTN in my app and I create notification with 2 buttons. One of them is RestoreBTN that it shows my ACTIVITY class. Now as I click on StopBTN, this error shows.

EDIT: There is NullPointer error in handleIntent method.

private void handleIntent(Intent intent) {
    final String a = intent.getStringExtra(EXTRA_NOTE);
    if (a != null) {
        switch (a) {
            case NOTE_RESTORE:
                tv.setText(timeString);
                notificationManager.cancel(notification_id);
                break;

            case NOTE_CLOSE:
                countDownTimer.cancel();
                isRunning = false;
                notificationManager.cancel(notification_id);
                break;
        }
    }

Possible duplicate of [What is a NullPointerException, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — sushildlh, Nov 26 '16 at 10:25
At which line is the crash? Please show the complete stacktrace. — K Neeraj Lal, Nov 26 '16 at 11:10
Create different intents viz `resultIntent1`, `resultIntent2`, for different actions. Also try `resultIntent.setAction()` and `resultIntent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);` — K Neeraj Lal, Nov 26 '16 at 11:50

Yaroslav Mytkalyk · Accepted Answer · 2016-11-27T10:34:09.110

You might want to set a constant for extra key, to avoid typos or something that looks like A but typed in wrong language. Also it's good to have constants for actions

private static final String EXTRA_A = "A";
private static final String A_RESTORE = "restore";
private static final String A_CLOSE = "close";

I don't know if you do, but not call onNewIntent() manually. Also onNewIntent() might not be called if your Activity is destroyed when you click on notification. You need to make two entries to check for intent, one for when activity is already running and you get onNewIntent(), and one if it's re-created and you get intent in onCreate()

@Override
protected void onCreate(Bundle b) {
    super.onCreate(b);
    // init views and stuff, and in final onCreate line handle the intent
    handleIntent(getIntent());
}

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent); // Make sure to call super
    handleIntent(intent);
}

The crash means that your Intent does not really contain extra "A". You cannot use switch on a null string, thus you'd be safe if you check if A is null.

private void handleIntent(Intent intent) {
    final String a = intent.getStringExtra(EXTRA_A);
    if (a != null) {
        switch (a) {
           case A_RESTORE:
               ...

           case A_CLOSE:
               ...

Do not modify the same intent for different PendingIntents. They are mutable and getActivity() does not create a defensive copy.

final Intent resultIntentRestore = new Intent(this, Adult1Activity.class);
resultIntentRestore.putExtra(EXTRA_A, A_RESTORE);
PendingIntent restoreIntent = PendingIntent.getActivity(Adult1Activity.this, 
        0, resultIntentRestore, PendingIntent.FLAG_UPDATE_CURRENT);

final Intent resultIntentClose = new Intent(this, Adult1Activity.class);
resultIntentClose.putExtra(EXTRA_A, A_CLOSE);
PendingIntent closeIntent = PendingIntent.getActivity(Adult1Activity.this, 
        2, resultIntentClose, PendingIntent.FLAG_UPDATE_CURRENT);

as you know i use your code, but now time there is a nullPointer error in `handleIntent` method.what should i do? would you please give me your email? — , Dec 02 '16 at 17:03
@MinaDahesh you're probably using getIntent() from outside onCreate() or added something else to `handleIntent()` that's causing it. I shall not post my email here, but you can contact me via Facebook, link in my bio. — Yaroslav Mytkalyk, Dec 02 '16 at 18:56
i use your code.you use `getIntent()` in `handleIntent(getIntent());` in onCreate method. although i send you my code and questions in your facebook messenger. would you please check it? thanks — , Dec 03 '16 at 13:15

NullPointerException in android: how to set context?

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