有没有办法在 FirebaseMessagingService 中获取 LifecycleOwner

Question

我正在开发一个聊天应用程序，并且正在使用 Firebase 云消息传递通知。 我发现最好将我的通知（通知信息）保存在本地数据库（即 Room）中，这样它可以帮助我处理徽章计数和特定聊天通知的清除。

步骤：

1. 设置我的 FirebaseMessagingService 并进行测试。 （成功获取我的通知）；
2. 设置 Room 数据库并测试以插入和获取所有数据 (LiveData)（运行良好）；
3. 我想观察 MyFirebaseMessagingService 中的 liveData，但要做到这一点，我需要一个 LivecycleOwner，我不知道从哪里得到它。

我在 google 上进行了搜索，但唯一的解决方案是使用 LifecycleService，但我需要 FirebaseMessagingService 来进行通知。

这是我的代码：

//Room Database class
private static volatile LocalDatabase INSTANCE;
private static final int NUMBER_OF_THREADS = 4;
public static final ExecutorService taskExecutor =
        Executors.newFixedThreadPool(NUMBER_OF_THREADS);

public static LocalDatabase getDatabase(final Context context) {
    if (INSTANCE == null) {
        synchronized (RoomDatabase.class) {
            if (INSTANCE == null) {
                INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
                        LocalDatabase.class, "local_database")
                        .build();
            }
        }
    }
    return INSTANCE;
}
public abstract  NotificationDao dao();




//DAO interface
@Insert
void insert(NotificationEntity notificationEntity);

@Query("DELETE FROM notificationentity WHERE trade_id = :tradeId")
int clearByTrade(String  tradeId);

@Query("SELECT * FROM notificationentity")
LiveData<List<NotificationEntity>> getAll();




//Repository class{}
private LiveData<List<NotificationEntity>> listLiveData;

public Repository() {
    firestore = FirebaseFirestore.getInstance();
    storage = FirebaseStorage.getInstance();
}
public Repository(Application application) {
    LocalDatabase localDb = LocalDatabase.getDatabase(application);
    dao = localDb.dao();
    listLiveData = dao.getAll();
}
...
public void saveNotificationInfo(@NonNull NotificationEntity entity){
    LocalDatabase.taskExecutor.execute(() -> {
        try {
            dao.insert(entity);
            H.debug("NotificationData saved in local db");
        }catch (Exception e){
            H.debug("Failed to save NotificationData in local db: "+e.getMessage());
        }
    });
}

public LiveData<List<NotificationEntity>> getNotifications(){return listLiveData;}

public void clearNotificationInf(@NonNull String tradeId){
    LocalDatabase.taskExecutor.execute(() -> {
        try {
            H.debug("trying to delete rows for id :"+tradeId+"...");
            int n = dao.clearByTrade(tradeId);
            H.debug("Cleared: "+n+" notification info from localDatabase");
        }catch (Exception e){
            H.debug("Failed clear NotificationData in local db: "+e.getMessage());
        }
    });
}




//ViewModel class{}
private Repository rep;
private LiveData<List<NotificationEntity>> list;

public VModel(@NonNull Application application) {
    super(application);
    rep = new Repository(application);
    list = rep.getNotifications();
}

public void saveNotificationInfo(Context context, @NonNull NotificationEntity entity){
    rep.saveNotificationInfo(entity);
}
public LiveData<List<NotificationEntity>> getNotifications(){
    return rep.getNotifications();
}
public void clearNotificationInf(Context context, @NonNull String tradeId){
    rep.clearNotificationInf(tradeId);
}




and finally the FiebaseMessagingService class{}
private static final String TAG = "MyFireBaseService";
private static final int SUMMARY_ID = 999;
private SoundManager sm;
private Context context;
private  final String  GROUP_KEY = "com.opendev.xpresso.group_xpresso_group_key";
private Repository rep;
private NotificationDao dao;

@Override
public void onCreate() {
    super.onCreate();
    context = this;
    rep = new Repository();
}

/**
 * Called if InstanceID token is updated. This may occur if the security of
 * the previous token had been compromised. Note that this is called when the InstanceID token
 * is initially generated so this is where you would retrieve the token.
 */
@Override
public void onNewToken(@NonNull String s) {
    super.onNewToken(s);
}

@Override
public void onMessageReceived(@NonNull RemoteMessage remoteMessage) {
    super.onMessageReceived(remoteMessage);
    H.debug("OnMessageReceived...");
    try {
        Map<String, String> data = remoteMessage.getData();

        if (Objects.requireNonNull(data.get("purpose")).equals("notify_message")) {

            String ChatId
            if ((chatId=data.get("chatId"))==null){
                H.debug("onMessageReceived: tradeId null! Aborting...");
                return;
            }

            FirebaseFirestore db = FirebaseFirestore.getInstance();
            Task<DocumentSnapshot> tradeTask = db.collection("activeTrades").document(chatTask).get();
            Task<DocumentSnapshot> userTask = db.collection("users")
                    .document(FirebaseAuth.getInstance().getCurrentUser().getUid()).get();

            Tasks.whenAllSuccess(chatTask, userTask).addOnSuccessListener(objects -> {

                if (!((DocumentSnapshot)objects.get(0)).exists() || !((DocumentSnapshot)objects.get(1)).exists()){
                    H.debug("OnMessageReceived: querying data failed:  NOT EXISTS");
                    return;
                }
                Chat chat = ((DocumentSnapshot)objects.get(0)).toObject(Trade.class);
                MainActivity.USER = ((DocumentSnapshot)objects.get(1)).toObject(User.class);


                //Now we got all the needed info we cant process the notification
                //Saving the notification locally and updating badge count
                //then notify for all the notification in localDatabase

                    NotificationEntity entity = new NotificationEntity();
                    entity.setNotificationId(getNextNotificationId());
                    entity.setTradeId(tradeId);
                    entity.setChanelId(context.getResources().getString(R.string.channel_id));
                    entity.setTitle(data.get("title"));
                    entity.setMessage(data.get("message"));
                    entity.setPriority(NotificationCompat.PRIORITY_HIGH);
                    entity.setCategory(NotificationCompat.CATEGORY_MESSAGE);
                    rep.saveNotificationInfo(entity);
                    rep.getNotifications().observe(HOW_TO_GET_THE_LIVECYCLE_OWNER, new Observer<List<NotificationEntity>>() {
                        @Override
                        public void onChanged(List<NotificationEntity> notificationEntities) {
                            //
                        }
                    });
            }).addOnFailureListener(e -> H.debug("OnMessageReceived: querying data failed:  "+e.getMessage()));
        }
    }catch (Exception e){H.debug(e.getMessage());}
}

Answer 1

我回答我自己的问题只是为了展示我的替代解决方法。 我相信 liveDataObserver 对我来说仍然是最好的方法，但是直到有人通过给我提供在 FirebaseMessagingService 中获取 LivecycleOwner 的解决方案来帮助我，我将为我的 insert() and my getAll() 使用自定义侦听器@

点赞关注

public interface RoomInsertListener{
    void onInsert();
}
public interface RoomGetListener{
    void onGet(List<NotificationEntity> list);
}

然后按如下方式在 FirebaseMessagingService 中使用它

NotificationEntity entity = new NotificationEntity();
    entity.setNotificationId(getNextNotificationId());
    entity.setTradeId(tradeId);
    entity.setChanelId(context.getResources().getString(R.string.channel_id));
    entity.setTitle(data.get("title"));
    entity.setMessage(data.get("message"));
    entity.setPriority(NotificationCompat.PRIORITY_HIGH);
    entity.setCategory(NotificationCompat.CATEGORY_MESSAGE);
    rep.saveNotificationInfo(entity, () -> rep.getNotifications(list -> {
        ShortcutBadger.applyCount(context, list.size());
        H.debug(list.size()+" notifications in Database: applied badge count...");
        for (NotificationEntity e:list){
            H.debug("id:"+e.getNotificationId()+" trade: "+e.getTradeId());
        }
    }));