Firebase数据库backgroundservice错误

Question

我正在开发一个用于发出产品请求的应用。更像是一个购物应用程序。当管理员发布一个时，用户将获得优惠。 我使用了firebase并创建了一个名为offers的根，并在商品节点下添加了商品。

我创建了一个firebasebackground侦听器服务并添加了onChildEventListener。当发布新的报价时，将通知用户该报价。

Firebasebackgroundservice.java:
public class FirebaseBackgroundService extends Service {

    private DatabaseReference f;
    NotificationManager manager;
    Notification myNotication;
    private TinyDB database;

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent,int flags,int startId) {
        super.onCreate();
        manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        database=new TinyDB(getApplicationContext());
        FirebaseApp.initializeApp(getApplicationContext());
        f= FirebaseDatabase.getInstance().getReference();
        final DatabaseReference foff=f.child("offers");

        foff.limitToLast(1).addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                ArrayList<String>offarray=new ArrayList<String>();
                offarray=database.getListString("offdata");
                if(!offarray.contains(dataSnapshot.getKey())){
                    offarray.add(dataSnapshot.getKey());
                    database.putListString("offdata",offarray);
                    Map<String, Object> newPost = (Map<String, Object>) dataSnapshot.getValue();
                    String title=newPost.get("title").toString();
                    String code=newPost.get("code").toString();
                    postNotif(title,code);
                }

            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        //Order updates
        String uname=database.getString("uname");
        final DatabaseReference fupd=f.child("users").child(uname).child("notif");
        fupd.limitToLast(1).addChildEventListener(new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                ArrayList<String>offarray=new ArrayList<String>();
                offarray=database.getListString("updata");
                if(!offarray.contains(dataSnapshot.getKey())){
                    offarray.add(dataSnapshot.getKey());
                    database.putListString("updata",offarray);
                    Map<String, Object> newPost = (Map<String, Object>) dataSnapshot.getValue();
                    String title=newPost.get("title").toString();
                    String code=newPost.get("code").toString();
                    updateNotif(title,code);
                }

            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {

            }

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {

            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

        return START_STICKY;
    }

    private void postNotif(String title,String descp) {
        Context context=getApplicationContext();
        Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        Bitmap icon = BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher);
        try {
            int smallIcon = R.drawable.ic_card;
            long when = System.currentTimeMillis();
            CharSequence contentTitle = title;
            CharSequence contentText = descp;
            Intent notificationIntent = new Intent(context,OfferActivity.class);
            PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);
            NotificationManager notificationManager =(NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context)
                    .setWhen(when)
                    .setContentText(contentText)
                    .setContentTitle(contentTitle)
                    .setSmallIcon(smallIcon)
                    .setAutoCancel(true)
                    .setTicker(contentTitle)
                    .setLargeIcon(icon)
                    .setContentIntent(pendingIntent)
                    .setSound(alarmSound);
            notificationManager.notify((int) when, notificationBuilder.build());
        } catch (Exception e) {
            Log.e("Notification Exception", e.getMessage());
        }
    }
    private void updateNotif(String title,String descp) {
        Context context=getApplicationContext();
        Bitmap icon = BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher);
        Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        try {
            int smallIcon = R.drawable.ic_file_upload;
            long when = System.currentTimeMillis();
            CharSequence contentTitle = title;
            CharSequence contentText = descp;
            Intent notificationIntent = new Intent(context,Notifications.class);
            PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, notificationIntent, 0);
            NotificationManager notificationManager =(NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context)
                    .setWhen(when)
                    .setContentText(contentText)
                    .setContentTitle(contentTitle)
                    .setSmallIcon(smallIcon)
                    .setAutoCancel(true)
                    .setTicker(contentTitle)
                    .setLargeIcon(icon)
                    .setContentIntent(pendingIntent)
                    .setSound(alarmSound);
            notificationManager.notify((int) when, notificationBuilder.build());
        } catch (Exception e) {
            Log.e("Notification Exception", e.getMessage());
        }
    }
    @Override
    public void onDestroy(){
        super.onDestroy();
        startService(new Intent(this,FirebaseBackgroundService.class));
    }

}

该应用程序工作正常，但我在这里遇到两个问题： 1.最初启动服务时，会显示通知。但有时服务器的服务是killed。重新启动服务时，不会显示通知。该服务正在被杀死，并且很长时间没有重新启动。 2.服务childAddedListener后未调用resumes，因此通知也未显示

该应用程序在首次启动服务时运行良好。一旦服务被终止，通知就不会显示，childaddedlistener无法正常工作

请帮我解决这个问题。我经常搜索firebasebackgroundservice，但结果却是这样。谢谢。