FCM notification message are not received in android Oreo version?

Question

I have send FCM notification from server to users. It works fine(until api 25) but in Oreo when the application have not in background(services are closed) (or) completely close

Answer 1

You can use below class for generating notification in lower and upper version of android(Tested from 4.2(Jelly Bean) to 8.1.1(Oreo)).

public final class NotificationHelper extends Thread {

    private Context context;
    private NotificationManager notifManager;
    private NotificationCompat.Builder notification_compact;
    private Notification.Builder notification_builder;
    private int OREO_NOTIFICATION_TYPE = 2; //setting default notificaiton type 2, as 1 is not for constant updating
    //put string channel name and id in **<>**
    private static final String CHANNEL_ONE_ID = "";
    private static final String CHANNEL_ONE_NAME = "";
    private static final String CHANNEL_TWO_ID = "";
    private static final String CHANNEL_TWO_NAME = "";
    private String title = "", message = "";


    /**
     * @param context content of activity
     * @param title   title for notification_compact
     * @param message message to show in notification_compact
     */
    public NotificationHelper(Context context, String title, String message) {
        this.context = context;
        this.title = title;
        this.message = message;
        notifManager = getManager();
    }


    @Override
    public void run() {
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N_MR1) {
            //do stuff for oreo
            createChannels();
            postNotificationAboveV25(OREO_NOTIFICATION_TYPE, title);
        } else {
            //do stuff for other versions
            postNotificationUptoV25();
        }
    }


    //method to show notificaiton above nougat
    private void postNotificationAboveV25(int id, String title) {
        notification_builder = getNotificatonBuilder(id, title);

        if (notification_builder != null) {
            getManager().notify(id, notification_builder.build());
        }
    }


    //get pending intent to launch activity
    private PendingIntent getPendingIntent() {

        Intent startActivity = context.getPackageManager()
                .getLaunchIntentForPackage(context.getPackageName())
                .setPackage(null)
                .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);

        return PendingIntent.getActivity(context, 0, startActivity, 0);

//        Intent resultIntent = new Intent(context, ActionActivity.class);
//        return PendingIntent.getActivity(context, AppHelper.NOTIFICATION_ID, resultIntent, PendingIntent.FLAG_UPDATE_CURRENT);
    }


    //method to get notification builder above nougat
    private Notification.Builder getNotificatonBuilder(int id, String title) {
        switch (id) {
            case 1:
                return notification_builder = getNotification1(title, message);

            case 2:
                return notification_builder = getNotification2(title, message);

            default:
                return notification_builder = getNotification2(title, message);
        }
    }


    //Create the notification_compact that’ll be posted to Channel One
    //use this one if your notification is a type of push notificaiton
    //                              or
    //if you are not updating it in continues intervals like every 4 or 5 seconds(ex. Timer)
    @SuppressLint("NewApi")
    private Notification.Builder getNotification1(String title, String body) {
        return new Notification.Builder(context, CHANNEL_ONE_ID)
                .setContentTitle(title)
                .setContentText(body)
                .setSmallIcon(R.drawable.app_icon)
                .setAutoCancel(true)
                .setTicker(title + AppHelper.getMessage(R.string.started))
                .setColor(AppHelper.getColor(context, R.color.colorPrimary))
                .setContentIntent(getPendingIntent());
    }


    //Create the notification_compact that’ll be posted to Channel Two
    //use this for continues intervals or updating continuesly
    @SuppressLint("NewApi")
    private Notification.Builder getNotification2(String title, String body) {
        return new Notification.Builder(context, CHANNEL_TWO_ID)
                .setContentTitle(title)
                .setContentText(body)
                .setTicker(title + AppHelper.getMessage(R.string.started))
                .setSmallIcon(R.drawable.app_icon)
                .setAutoCancel(true)
                .setColor(AppHelper.getColor(context, R.color.colorPrimary))
                .setContentIntent(getPendingIntent());
    }


    //method to post notification upto Nougat i.e., below api level 26
    @SuppressLint("NewApi")
    private void postNotificationUptoV25() {
        notification_compact = new NotificationCompat.Builder(context);
        notification_compact.setAutoCancel(true);
        notification_compact.setSmallIcon(R.drawable.app_icon);
        notification_compact.setTicker(title + AppHelper.getMessage(R.string.started));
        notification_compact.setContentTitle(title);
        notification_compact.setContentText(message);
        notification_compact.setColor(AppHelper.getColor(context, R.color.colorPrimary));
        notification_compact.setContentIntent(getPendingIntent());
//        notification_compact.setWhen(1506067106762L);

        getManager().notify(AppHelper.NOTIFICATION_ID, notification_compact.build());
    }


    //method to update notification
    public void updateNotification(String time) {

        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N_MR1) {
            //update above NOUGAT V25
            if (notification_builder != null) {
                notification_builder.setContentText(message + "  " + time);
                getManager().notify(AppHelper.NOTIFICATION_ID, notification_builder.build());
            }
        } else {
            //update below NOUGAT V25
            if (notification_compact != null) {
                notification_compact.setContentText(message + "  " + time);
                getManager().notify(AppHelper.NOTIFICATION_ID, notification_compact.build());
            }
        }
    }

    //method to update remainting notification
    public void updateRemainingNotification(String time) {

        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N_MR1) {
            //update above NOUGAT V25
            if (notification_builder != null) {
                notification_builder.setContentText(time + AppHelper.getMessage(R.string.remaining));
                getManager().notify(AppHelper.NOTIFICATION_ID, notification_builder.build());
            }
        } else {
            //update below NOUGAT V25
            if (notification_compact != null) {
                notification_compact.setContentText(time + AppHelper.getMessage(R.string.remaining));
                getManager().notify(AppHelper.NOTIFICATION_ID, notification_compact.build());
            }
        }
    }


    //method to create channels which is necessary above Nougat(API - 25) i.e., at Oreo(API - 26)
    @SuppressLint("NewApi")
    private void createChannels() {

        NotificationChannel notificationChannel = new NotificationChannel(CHANNEL_ONE_ID,
                CHANNEL_ONE_NAME, notifManager.IMPORTANCE_DEFAULT);
        notificationChannel.enableLights(true);
        notificationChannel.setLightColor(Color.RED);
        notificationChannel.setShowBadge(true);
        notificationChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
        getManager().createNotificationChannel(notificationChannel);

        NotificationChannel notificationChannel2 = new NotificationChannel(CHANNEL_TWO_ID,
                CHANNEL_TWO_NAME, notifManager.IMPORTANCE_DEFAULT);
        notificationChannel2.enableLights(false);
        notificationChannel2.enableVibration(true);
        notificationChannel2.setLightColor(Color.RED);
        notificationChannel2.setShowBadge(false);
        getManager().createNotificationChannel(notificationChannel2);

    }


    //method to get Object of Notification Manager
    private NotificationManager getManager() {
        if (notifManager == null)
            notifManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);

        return notifManager;
    }


    /**
     * call this method to destroy notification
     */
    public void destroyNotification() {
        if (notifManager != null)
            notifManager.cancel(AppHelper.NOTIFICATION_ID);
    }
}

Just call this class from FCM, with context and msg. As its a thread class you can update the notification constantly also.

Don't forget to call destroyNotification() method, when your work ends.

You can discover and make changes in it, as you like