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。大厅集合中的大厅包含一个ID，创建者，creationDate和所有成员的数组（对用户集合中用户对象的DocumentReferences）。用户包含一个ID，名称，邮件和一个活动的大厅。现在，当我更新Firestore中的条目时，那里似乎是正确的。.但是当我收到realtimeUpdate（通过添加SnapshotListener）时，成员数组似乎为空..但是我只是插入了阵列用户已被保存到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
我也有一个本地HashMap或多或少地缓存对象，因此我不必总是从Firestore加载对象（我知道Firestore库中已经有一个缓存了。。但是我认为我需要自己的缓存）
此刻，我将更改直接写到Firestore并等待它们通过RealtimeUpdate返回以更新本地对象。我还尝试过更新本地对象，然后将它们写入Firestore ..但是我仅将我的用户附加到Members-Array，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“常规”数据，但不提供引用数组。最初从Firestore加载数据时，我会获取Firestore的实际数据（不为空）。但是我想获取整个文档，包括“普通”数据（id，creationDate，...）和成员的整个数组。
我已经花了1.5天的时间来解决此问题，但我不知道是怎么回事。
答案 0 :(得分：0)
没关系，我遇到了我的错误。。。。。。。。。。
在我更新对象的部分中，当Firestore更改时。.我使用了错误/旧的DocumentSnapshot。所以我使用了初始成员数组而不是我的新更新的：D
应为：
List<DocumentReference> update_docmems = (List<DocumentReference>) snapshot.get(FIRESTORE_DOCUMENT_MEMBER);
代替：
List<DocumentReference> update_docmems = (List<DocumentReference>) documentSnapshot.get(FIRESTORE_DOCUMENT_MEMBER);
现在我可以正确获取更新了：D