Answers for "android push notifications"

android create notification

NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(yourContext.getApplicationContext(), "notify_001");
Intent ii = new Intent(yourContext.getApplicationContext(), YourMainActivty.class);
PendingIntent pendingIntent = PendingIntent.getActivity(yourContext, 0, ii, 0);

NotificationCompat.BigTextStyle bigText = new NotificationCompat.BigTextStyle();
bigText.bigText(notificationsTextDetailMode); //detail mode is the "expanded" notification
bigText.setBigContentTitle(notificationTitleDetailMode);
bigText.setSummaryText(usuallyAppVersionOrNumberOfNotifications); //small text under notification

mBuilder.setContentIntent(pendingIntent);
mBuilder.setSmallIcon(R.mipmap.ic_launcher); //notification icon
mBuilder.setContentTitle(notificationTitle); //main title
mBuilder.setContentText(notificationText); //main text when you "haven't expanded" the notification yet
mBuilder.setPriority(Notification.PRIORITY_MAX);
mBuilder.setStyle(bigText);

NotificationManager mNotificationManager = (NotificationManager) yourContext.getSystemService(Context.NOTIFICATION_SERVICE);

NotificationChannel channel = new NotificationChannel("notify_001",
                                                      "Channel human readable title",
                                                      NotificationManager.IMPORTANCE_DEFAULT);
if (mNotificationManager != null) {
  mNotificationManager.createNotificationChannel(channel);
}

if (mNotificationManager != null) {
  mNotificationManager.notify(0, mBuilder.build());
}

android foreground push notification

// When app is in foreground, notifications are not generated themselves. You need to write some additional code. When message is received onMessageReceived() method is called where you can generate the notification. Here is the code:

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        Log.d("msg", "onMessageReceived: " + remoteMessage.getData().get("message"));
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT);
        String channelId = "Default";
        NotificationCompat.Builder builder = new  NotificationCompat.Builder(this, channelId)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle(remoteMessage.getNotification().getTitle())
                .setContentText(remoteMessage.getNotification().getBody()).setAutoCancel(true).setContentIntent(pendingIntent);;
        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(channelId, "Default channel", NotificationManager.IMPORTANCE_DEFAULT);
            manager.createNotificationChannel(channel);
        }
        manager.notify(0, builder.build());
    }
}