【发布时间】：2019-06-22 12:11:28
【问题描述】：
我正在编写一个游戏，用户可以在其中加入一个大厅一起玩。因此我更新了存储在 Firestore 中的大厅和用户。 Lobby-Collection 中的 Lobbys 包含一个 Id、creator、creationDate 和所有成员的数组（对用户集合中的用户对象的文档引用）。用户包含 ID、姓名、邮件和活动大厅。现在，当我更新 Firestore 中的条目时，在那里（Firestore）它们似乎是正确的.. 但是当我收到 realtimeUpdate（通过添加 SnapshotListener）时，成员数组似乎是空的.. 但我只是插入了用户到阵列，他们被保存到 Firestore..
也许很高兴知道：我将从 Firestore 获得的数据集转换为本地 Java 对象，以便更好地处理 UI 内容
我还有一个本地 HashMap 来或多或少地缓存对象，所以我不必总是从 Firestore 加载（我知道 Firestore 库中已经有一个缓存......但我想我需要自己的）
目前，我将更改直接写入 Firestore，并等待它们通过 RealtimeUpdate 返回，然后更新我的本地对象。我还尝试更新我的本地对象，然后将它们写入 Firestore.. 但是我只将我的用户附加到成员数组中，并且该数组包含同一用户的多个引用..
/**
* Get a Lobby Object from a DocumentSnapshot from Firestrore
* If the Object already exists it will be loaded from the "CacheMap"
*
* @param documentSnapshot DocumentSnapshot with the data from the Firestore
* @param feedback a method to call when the Lobby was retrieved
*/
public static void getLobbyByDocSnap(DocumentSnapshot documentSnapshot, IFeedback feedback) {
final String METHOD = TAG + " #getLobbyByDocSnap";
String lobby_id = documentSnapshot.getString(FIRESTORE_DOCUMENT_ID);
if (allLoadedLobbys.containsKey(lobby_id)) {
Log.d(METHOD, "found object in map for id: " + lobby_id);
feedback.trigger(allLoadedLobbys.get(lobby_id));
return;
}
Log.d(METHOD, "Could not find in Map.. generate through data");
Lobby lobby = new Lobby();
lobby.setId(lobby_id);
lobby.setPrivateLobby(documentSnapshot.getBoolean(FIRESTORE_DOCUMENT_PRIVATELOBBY));
lobby.setCreationDate(documentSnapshot.getDate(FIRESTORE_DOCUMENT_CREATIONDATE));
allLoadedLobbys.put(lobby.getId(), lobby);
//create all Members of the Lobby as User Objects
final List<User> members = new ArrayList<>();
List<DocumentReference> docmems = (List<DocumentReference>) documentSnapshot.get(FIRESTORE_DOCUMENT_MEMBER);
Log.d(METHOD, "get all members of lobby: " + lobby_id);
for (final DocumentReference docmem : docmems) {
/*docmem.collection(FIRESTORE_DOCUMENT_MEMBER).get()
.addOnSuccessListener(queryDocumentSnapshots -> {
Log.d(METHOD, "Found Members for: "+lobby_id+": "+Arrays.toString(queryDocumentSnapshots.getDocuments().toArray()));
//Convert DocumentReference to User-Object
for (DocumentSnapshot document : queryDocumentSnapshots.getDocuments()) {
Log.d(METHOD, "Get User Object from "+UserManager.class.getCanonicalName());
UserManager.getUserByDocSnap(document, o -> members.add((User) o));
}
});*/
UserManager.getUserByRef(docmem, o -> members.add((User) o));
}
lobby.setMember(members);
Log.d(METHOD, "Start getting the Creator of this Lobby: " + lobby_id);
//create an User-Object for the Creator
UserManager.getUserByRef((DocumentReference) documentSnapshot.get(FIRESTORE_DOCUMENT_CREATOR), o -> {
User creator = (User) o;
lobby.setCreator(creator);
Log.d(METHOD, "Got the Creator, now get the artist for: " + lobby_id);
UserManager.getUserByRef((DocumentReference) documentSnapshot.get(FIRESTORE_DOCUMENT_ARTIST), a -> {
User artist = (User) a;
Log.d(METHOD, "Got the Artist. All Infos collected for: " + lobby_id);
//Create The Lobby-Object
lobby.setArtist(artist);
Log.d(METHOD, "Save the Lobby to the CacheMap: " + lobby.toString());
//add it to the given list and trigger the feedback
feedback.trigger(lobby);
});
});
documentSnapshot.getReference().addSnapshotListener((snapshot, e) -> {
if (e != null) {
Log.w(METHOD+"+new", "Listen failed.", e);
return;
}
if (snapshot != null && snapshot.exists()) {
Log.d(METHOD + "*new", "Current data: " + snapshot.getData());
String update_lobby_id = snapshot.getString(FIRESTORE_DOCUMENT_ID);
Lobby update_lobby = allLoadedLobbys.get(update_lobby_id);
update_lobby.setCreationDate(snapshot.getDate(FIRESTORE_DOCUMENT_CREATIONDATE));
update_lobby.setPrivateLobby(snapshot.getBoolean(FIRESTORE_DOCUMENT_PRIVATELOBBY));
UserManager.getUserByRef(snapshot.getDocumentReference(FIRESTORE_DOCUMENT_ARTIST), o -> update_lobby.setArtist((User) o));
UserManager.getUserByRef(snapshot.getDocumentReference(FIRESTORE_DOCUMENT_CREATOR), o -> update_lobby.setCreator((User) o));
List<User> update_member = update_lobby.getMember();
update_member.clear();
List<DocumentReference> update_docmems = (List<DocumentReference>) documentSnapshot.get(FIRESTORE_DOCUMENT_MEMBER);
//update_lobby.setMember(update_member);
Log.d(METHOD+"*new", "get all updated members of lobby: " + update_lobby_id);
Log.d(METHOD+"*new", "members DocRef List: " + update_docmems);
/*for (final DocumentReference update_docmem : update_docmems) {
Log.d(METHOD+"*new", update_docmem.getId());
UserManager.getUserByRef(update_docmem, o -> {
Log.d(METHOD+"*new",((User) o).toString());
update_lobby.addMember((User) o);
});
}*/
getMemberList(update_docmems, new ArrayList<>(), o -> {
List<User> mems = (List<User>) o;
update_lobby.getMember().clear();
update_lobby.getMember().addAll(mems);
});
} else {
Log.d(METHOD+"*new", "Current data: null");
}
});
}
private static void getMemberList(List<DocumentReference> update_docmems, List<User> member, IFeedback feedback){
final String METHOD = TAG + " #getMemberList";
/*if(null == member){
member = new ArrayList<>();
}*/
if(update_docmems.isEmpty()){
feedback.trigger(member);
return;
}
DocumentReference docref = update_docmems.get(0);
UserManager.getUserByRef(docref, o -> {
member.add((User) o);
Log.d(METHOD, o.toString());
update_docmems.remove(0);
getMemberList(update_docmems, member, feedback);
});
}
Realtime 仅提供“正常”数据，但不提供引用数组。当我最初从 Firestore 加载数据时，我得到了 Firestore 的实际数据（非空）。但我想获取整个文档，包括“正常”数据（id、creationDate、...）和整个成员数组。
我已经花了 1.5 天的时间来解决这个问题，我无法弄清楚，出了什么问题..
【问题讨论】：
标签： android google-cloud-firestore real-time-updates