Local notification occurs but doesn't appear on the screen

Question

Although the notifications sent by the application are high priority and grouped, when frequent notifications are sent, the notifications begin to not shown after a while. When I examine the logs in my code, I can see that the local notification has occurred. Why are the notifications not showing after sending frequent notifications?

    fun getChatChannels(): MutableList<NotificationChannel> {

    val chatChannels = mutableListOf<NotificationChannel>()

    val chatChannel = NotificationChannel(
        IM_CHANNEL_ID,
        Application.getString(R.string.chat_channel_name),
        NotificationManager.IMPORTANCE_HIGH
    )

    chatChannel.setShowBadge(false)
    chatChannel.group = MESSAGE_GROUP_ID

    chatChannels.add(chatChannel)

    return chatChannels }



    private fun getChannelList(): MutableList<NotificationChannel> {

    val channelList = mutableListOf<NotificationChannel>()
    channelList.addAll(getChatChannels())

    return channelList
    }


    fun createGroupsAndChannels() {

    // Create the NotificationChannel, but only on API 26+ because
    // the NotificationChannel class is new and not in the support library
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

        val notificationManager =
            Application.instance.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

        notificationManager.createNotificationChannelGroups(getGroupList())
        notificationManager.createNotificationChannels(getChannelList())
    }
    Log.d(TAG, "Channels and groups created")
     }



    fun showChatNotification(destinationAddress: String, messageId: String, message: String) {
     ThreadManager.createUITask {
            val name = if (domainContact != null) {
                "${domainContact.firstName} ${domainContact.lastName}"
            } else {
                destinationAddress
            }

            val notificationIntent = Intent(Application.instance, MainActivity::class.java)
            notificationIntent.putExtra(
                Application.getString(R.string.key_conversation_participant),
                destinationAddress
            )
            notificationIntent.flags = Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS

            val pendingIntent = PendingIntent.getActivity(
                Application.instance,
                destinationAddress.hashCode(),
                notificationIntent,
                PendingIntent.FLAG_UPDATE_CURRENT
            )
            val notificationId = UUID.randomUUID().hashCode()

            val builder = NotificationCompat.Builder(Application.instance, IM_CHANNEL_ID)
                .setSmallIcon(R.drawable.ic_notification_message)
                .setColor(ContextCompat.getColor(Application.instance, R.color.colorPrimary))
                .setContentTitle(name)
                .setContentText(message)
                .setStyle(
                    NotificationCompat.BigTextStyle() // Expandable-Collapsible notification
                        .bigText(message)
                )
                .setPriority(NotificationCompat.PRIORITY_HIGH)
                .setDefaults(NotificationCompat.DEFAULT_ALL)
                .setCategory(NotificationCompat.CATEGORY_MESSAGE)
                .setContentIntent(pendingIntent)
                .setVisibility(VISIBILITY_PUBLIC)
                .setAutoCancel(true)

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                builder.addAction(getChatNotificationReplyAction(destinationAddress, notificationId, messageId))
            }

            chatNotifications.add(mapOf(destinationAddress to notificationId))
            createNotifications(builder, notificationId)

            Log.d(TAG, "Chat notification created")
        } 


  private fun createNotifications(builder: NotificationCompat.Builder, notificationId: Int) {

        with(NotificationManagerCompat.from(Application.instance)) {
            notify(notificationId, builder.build())
        }
    }

Answer 1

did u create NotificationChannel if the android os is equal to or bigger than Oreo? /////////////////////////////////////////////////////////////////
I create a notification in the service and start the notification service when I want to update the notification message. I tested update every second for message value and the value will change over 50 times.

MyNotificationService.java

package com.urpackage.test;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;
import android.text.TextUtils;

import androidx.core.app.NotificationCompat;

public class MyNotificationService extends Service {
    Context mContext;
    Notification notification = null;
    private final int notificationId=12321;

    @Override
    public void onCreate() {
        super.onCreate();
        mContext=this.getApplicationContext();

    }

    @Override
    public void onDestroy() {
        NotificationManager notificationManager = (NotificationManager)mContext.getSystemService(mContext.NOTIFICATION_SERVICE);;
        notificationManager.cancel(notificationId);
        builder =null;
        super.onDestroy();

    }
    NotificationCompat.Builder builder =null ;
    private void createNotification(String message) {
        try {
            NotificationManager notificationManager = (NotificationManager)mContext.getSystemService(mContext.NOTIFICATION_SERVICE);
            if(builder==null)
            {
                String packageName=mContext.getClass().getPackage().getName();
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.addCategory(Intent.CATEGORY_LAUNCHER);
                intent.setClass(this, MainActivity.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
                //activityIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0, intent, PendingIntent.FLAG_MUTABLE);
                //Notification notification = null;
                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {

                    NotificationChannel notificationChannel = new NotificationChannel(
                            packageName,
                            "MyChannel",
                            NotificationManager.IMPORTANCE_DEFAULT);
                    //channelLove.setDescription("?????");
                    //channelLove.enableLights(true);
                    //channelLove.enableVibration(true);

                    notificationManager.createNotificationChannel(notificationChannel);

                    builder = new NotificationCompat.Builder(getApplication(), packageName)
                            .setAutoCancel(false).setOngoing(true)
                            .setSmallIcon(R.drawable.ic_baseline_play_circle_filled_24).setTicker("MyChannelN")
                            .setContentTitle("MyChannelN")
                            //.setContentText(message).
                            .setWhen(System.currentTimeMillis())
                            .setContentIntent(pendingIntent);
                } else {
                    builder = new NotificationCompat.Builder(getApplication(), packageName)
                            .setAutoCancel(false).setOngoing(true)
                            .setSmallIcon(R.drawable.ic_baseline_play_circle_filled_24).setTicker("MyChannelN")
                            .setContentTitle("MyChannelN")
                            //.setContentText(message).
                            .setWhen(System.currentTimeMillis())
                            .setContentIntent(pendingIntent)
                            .setPriority(NotificationCompat.PRIORITY_DEFAULT);
                }
            }
            // notificationId is a unique int for each notification that you must define
            builder.setContentText(message);
            notificationManager.notify(notificationId, builder.build());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Bundle bundle=null;
        if(intent!=null)
            bundle=intent.getExtras();
        String message="Running";
        if(bundle!=null)
            message=bundle.getString("NotificationMessage","Running");
        createNotification(message);

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }
}

To use the service

Intent MyNotificationServiceIntent = new Intent(this, >MyNotificationService.class); MyNotificationServiceIntent.putExtra("NotificationMessage", "your message"); startService(MyNotificationServiceIntent);