SHOW NOTIFICATION IN ANDROID

FOR OLDER DEVICES  < ANDROID OREO

 public void showNotification(Context context, String title, String body) {
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle(title)
                .setContentText(body);
        notificationManager.notify(1, mBuilder.build());
    }

FOR NEW DEVICES >= ANDROID OREO

private void showNotification(Context context, String title, String body) {
        NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel mChannel = new NotificationChannel("1", "MyChannel",NotificationManager.IMPORTANCE_HIGH);
            notificationManager.createNotificationChannel(mChannel);
        }
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context, "1")
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle(title)
                .setContentText(body);
        notificationManager.notify(1, mBuilder.build());
    }