等待 Cloud Firestore 任务结果

huangapple
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英文:

Wait for Cloud Firestore task result

问题

我正试图开发一种方法来访问 Cloud Firestore，读取用户数据并返回与之关联的映射。据我理解，它没有等待成功/失败监听器，我已经尝试将其更改为完全监听器，但结果是相同的。它跳过了这些监听器。
我知道这是一个异步过程，但我需要接收数据以在调用该方法的 Activity 中显示它们。

Settings Activity：

  1.     @Override
  2.     protected void onCreate(Bundle savedInstanceState) {
  3.         super.onCreate(savedInstanceState);
  4.         this.binding = ActivitySettingsBinding.inflate(getLayoutInflater());
  5.         this.fbUtils = new FirebaseHandler(this);
  6.         setContentView(binding.getRoot());
  7.     }
  9.     @Override
  10.     protected void onStart() {
  11.         super.onStart();
  12.         User user = fbUtils.getCurrentUser();
  13.         if (user == null) {
  14.             findUserOrLogout();
  15.         } else {
  16.             showUserData(user);
  17.         }
  18.     }

FirebaseHandler：

  1.     public User getCurrentUser() {
  2.         FirebaseUser user = auth.getCurrentUser();
  3.         if (user != null) {
  4.             this.userMap = getUserDBInfo(user.getUid());
  5.             this.profilePic = getUserPic(user.getUid());
  6.             if (this.userMap != null && this.profilePic != null) {
  7.                 return new User(user, userMap, profilePic);
  8.             }
  9.         }
  10.         return null;
  11.     }
  12.     
  13.     private Map<String, Object> getUserDBInfo(String uid) {
  14.         Log.d(TAG, "Getting user info for user '" + uid + "'");
  15.         DocumentReference docRef = db.collection("users").document(uid);
  16.         final Map<String, Object>[] userMap = new Map[]{null};
  17.         final boolean[] done = new boolean[]{false};
  18.         docRef.get().addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
  19.             @Override
  20.             public void onSuccess(DocumentSnapshot documentSnapshot) {
  21.                 if (documentSnapshot.exists()) {
  22.                     Log.d(TAG, "DocShot: " + documentSnapshot);
  23.                     userMap[0] = documentSnapshot.getData();
  24.                 } else {
  25.                     Log.d(TAG, "User's document not found");
  26.                 }
  27.             }
  28.         }).addOnFailureListener(new OnFailureListener() {
  29.             @Override
  30.             public void onFailure(@NonNull Exception e) {
  31.                 Log.d(TAG, "Couldn't get the Document");
  32.                 MainActivity.showToast("Couldn't get the Document", activity.getApplicationContext());
  33.             }
  34.         });
  35.         return userMap[0];
  36.     }

我在代码中做错了什么，还是有什么可以改变的地方使其工作起来？
提前感谢。

英文:

I'm trying to develop a method to access the Cloud Firestore, read a user's data and return the map associated to it. For what I understand, it is not waiting for the success/failure listener, and I already tried changing it for a complete listener but the result is the same. It skips through the listeners.
I know that this is a Assynchronous process, but I need to receive the data to show them on the Activity that calls the method.

Settings Activity:

  1.     @Override
  2. protected void onCreate(Bundle savedInstanceState) {
  3. super.onCreate(savedInstanceState);
  4. this.binding = ActivitySettingsBinding.inflate(getLayoutInflater());
  5. this.fbUtils = new FirebaseHandler(this);
  6. setContentView(binding.getRoot());
  7. }
  8. @Override
  9. protected void onStart() {
  10. super.onStart();
  11. User user = fbUtils.getCurrentUser();
  12. if (user == null) {
  13. findUserOrLogout();
  14. } else {
  15. showUserData(user);
  16. }
  17. }

FirebaseHandler

  1.     public User getCurrentUser() {
  2. FirebaseUser user = auth.getCurrentUser();
  3. if (user != null) {
  4. this.userMap = getUserDBInfo(user.getUid());
  5. this.profilePic = getUserPic(user.getUid());
  6. if (this.userMap != null &amp;&amp; this.profilePic != null) {
  7. return new User(user, userMap, profilePic);
  8. }
  9. }
  10. return null;
  11. }
  12. private Map&lt;String, Object&gt; getUserDBInfo(String uid) {
  13. Log.d(TAG, &quot;Getting user info for user &#39;&quot; + uid+&quot;&#39;&quot;);
  14. DocumentReference docRef = db.collection(&quot;users&quot;).document(uid);
  15. final Map&lt;String, Object&gt;[] userMap = new Map[]{null};
  16. final boolean[] done = new boolean[]{false};
  17. docRef.get().addOnSuccessListener(new OnSuccessListener&lt;DocumentSnapshot&gt;() {
  18. @Override
  19. public void onSuccess(DocumentSnapshot documentSnapshot) {
  20. if (documentSnapshot.exists()) {
  21. Log.d(TAG, &quot;DocShot: &quot; + documentSnapshot);
  22. userMap[0] = documentSnapshot.getData();
  23. } else {
  24. Log.d(TAG, &quot;User&#39;s document not found&quot;);
  25. }
  26. }
  27. }).addOnFailureListener(new OnFailureListener() {
  28. @Override
  29. public void onFailure(@NonNull Exception e) {
  30. Log.d(TAG, &quot;Couldn&#39;t get the Document&quot;);
  31. MainActivity.showToast(&quot;Couldn&#39;t get the Document&quot;, activity.getApplicationContext());
  32. }
  33. });
  34. return userMap[0];
  35. }

Am I doing something wrong in my code, or is there anything I can change to make this work?

Thanks in advance.

答案1

得分: 1

你必须在Firebase控制台内更改规则，以允许写入操作。

您需要按照以下步骤进行操作：

  1. 打开Firebase控制台，进入Database（数据库）。

  2. 在那里转到**Rules（规则）**选项卡，并编辑规则如下：

  1. {
  2.   "rules": {
  3.     ".read": true,
  4.     ".write": true
  5.   }
  6. }

这将允许您在数据库上执行写入操作。

如果您需要截屏，请告诉我。

英文:

You have to change the rules inside the Firebase console to allow a write operation.

You've to follow the steps given below to do so:-

  1. Open your Firebase Console and navigate to Database.

  2. There go to the Rules tab and edit the rules to following:-

  1. {
  2. &quot;rules&quot;: {
  3. &quot;.read&quot;: true,
  4. &quot;.write&quot;: true
  5. }
  6. }

This will allow you to perform write operations on your DB.

Please let me know if you will need screenshots.

答案2

得分: 0

如果您的数据库需要经过身份验证的用户才能读写数据库，请不要使用此处的其他答案。这将创建一个巨大的安全漏洞，允许任何拥有互联网连接的人完全读写数据库。

相反，您的代码应该在尝试进行任何查询之前确保用户已登录。这可以通过使用身份验证状态侦听器来实现，以便在用户登录时获得回调。只有在使用有效的用户对象调用此回调后，才能安全地进行需要身份验证的查询。

英文:

If your database requires an authenticated user to read and write the database then do use the other answer here. It will create a massive security hole that allows for anyone with an internet connection to fully read and write the database.

Your code should instead ensure that a user is signed in before trying to make any queries. This made possible by using an auth state listener to get a callback when the user is signed in. Only after this callback is invoked with a valid user object is it safe to make a query that requires authentication.

huangapple
  • 本文由 发表于 2020年8月15日 23:48:22
  • 转载请务必保留本文链接：https://go.coder-hub.com/63427953.html
  • android
  • google-cloud-firestore
  • java
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