如何从Android App中删除Firebase用户？

Question

我正在尝试在我的Android应用程序中编写删除用户方法，但每次执行它时都会遇到一些问题。当用户按下活动上的删除帐户按钮时，将执行此方法。我的应用与FirebaseUI Auth配合使用。

这是方法：

private void deleteAccount() {
    Log.d(TAG, "ingreso a deleteAccount");
    FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
    final FirebaseUser currentUser = firebaseAuth.getCurrentUser();

    currentUser.delete().addOnCompleteListener(new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            if (task.isSuccessful()) {
                Log.d(TAG,"OK! Works fine!");
                startActivity(new Intent(Main3WelcomeActivity.this, Main3Activity.class));
                finish();
            } 
        }
    }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {
            Log.e(TAG,"Ocurrio un error durante la eliminación del usuario", e);
        }
    });
}

1）当我执行该功能时，屏幕上会出现一个Smart Lock消息，用户再次登录。以下是此消息的屏幕截图。

2）在其他情况下，当用户登录很长时间时，该函数抛出一个Exception，如下所示：

06-30 00:01:26.672 11152-11152/com.devpicon.android.firebasesamples E/Main3WelcomeActivity: Ocurrio un error durante la eliminación del usuario
com.google.firebase.FirebaseException: An internal error has occured. [ CREDENTIAL_TOO_OLD_LOGIN_AGAIN ]
at com.google.android.gms.internal.zzacq.zzbN(Unknown Source)
at com.google.android.gms.internal.zzacn$zzg.zza(Unknown Source)
at com.google.android.gms.internal.zzacy.zzbO(Unknown Source)
at com.google.android.gms.internal.zzacy$zza.onFailure(Unknown Source)
at com.google.android.gms.internal.zzact$zza.onTransact(Unknown Source)
at android.os.Binder.execTransact(Binder.java:453)

我已经读过I have to re-authenticate的用户，但是当我使用Google登录时，我不确定该怎么做。

Answer 1

根据Firebase文档，可以使用delete()方法从Firebase中删除用户

在删除用户之前，请重新验证用户。

示例代码

     final FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();

        // Get auth credentials from the user for re-authentication. The example below shows
        // email and password credentials but there are multiple possible providers,
        // such as GoogleAuthProvider or FacebookAuthProvider.
        AuthCredential credential = EmailAuthProvider
                .getCredential("[email protected]", "password1234");

        // Prompt the user to re-provide their sign-in credentials
        user.reauthenticate(credential)
                .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
           user.delete()
            .addOnCompleteListener(new OnCompleteListener<Void>() {
                @Override
                public void onComplete(@NonNull Task<Void> task) {
                    if (task.isSuccessful()) {
                        Log.d(TAG, "User account deleted.");
                    }
                }
            });

   }
});

有关更多详细信息：https://firebase.google.com/docs/auth/android/manage-users#re-authenticate_a_user

如果你想用其他单一提供者重新认证，只需要为Provider更改下面的GoogleAuthProvider就是示例代码

GoogleAuthProvider.getCredential(googleIdToken,null);

Answer 2

首先，您需要在用户登录时存储身份验证令牌或密码。如果您的应用未提供诸如Google登录，Facebook登录或其他应用，则只需存储密码。

//If there's any, delete all stored content from this user on Real Time Database. 
yourDatabaseReferenceNode.removeValue();

//Getting the user instance.
final FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();

if (user != null) {
    //You need to get here the token you saved at logging-in time.
    String token = "userSavedToken";
    //You need to get here the password you saved at logging-in time.
    String password = "userSavedPassword";

    AuthCredential credential;

    //This means you didn't have the token because user used like Facebook Sign-in method.
    if (token == null) {
       credential = EmailAuthProvider.getCredential(user.getEmail(), password);
    } else {
       //Doesn't matter if it was Facebook Sign-in or others. It will always work using GoogleAuthProvider for whatever the provider.
       credential = GoogleAuthProvider.getCredential(token, null);
    }

    //We have to reauthenticate user because we don't know how long 
    //it was the sign-in. Calling reauthenticate, will update the 
    //user login and prevent FirebaseException (CREDENTIAL_TOO_OLD_LOGIN_AGAIN) on user.delete()
    user.reauthenticate(credential)
            .addOnCompleteListener(new OnCompleteListener<Void>() {
                    @Override
                    public void onComplete(@NonNull Task<Void> task) {
                        //Calling delete to remove the user and wait for a result.
                        user.delete().addOnCompleteListener(new OnCompleteListener<Void>() {
                            @Override
                            public void onComplete(@NonNull Task<Void> task) {
                                if (task.isSuccessful()) {
                                    //Ok, user remove
                                } else {
                                    //Handle the exception
                                    task.getException();
                                }
                            }
                        });
                    }
                });    
}        

Answer 3

Ansuita Jr.提供的答案非常精美，只是一个小问题是正确的。即使没有成功重新验证，用户也会被删除。这是因为我们使用

user.delete（）

在始终执行的onComplete（）方法中。因此，我们需要添加if检查来检查任务是否成功，如下所述

user.reauthenticate(credential)
          .addOnCompleteListener(new OnCompleteListener<Void>() {
             @Override
             public void onComplete(@NonNull Task<Void> task) {
                 if (task.isSuccessful()) {
                    Log.e("TAG", "onComplete: authentication complete");
                    user.delete()
                    .addOnCompleteListener (new OnCompleteListener<Void>() {
                           @Override
                           public void onComplete(@NonNull Task<Void> task) {
                                if (task.isSuccessful()) {
                                    Log.e("TAG", "User account deleted.");
                                } else {
                                    Log.e("TAG", "User account deletion unsucessful.");
                                }
                          }
                     });
                 } else {
                     Toast.makeText(UserProfileActivity.this, "Authentication failed", 
                               Toast.LENGTH_SHORT).show();
                 }
              }
         });

Answer 4

你的delete回调已经处理了失败的情况，为什么你以后添加addOnFailureListener？

尝试删除它，这样：

private void deleteAccount() {
    Log.d(TAG, "ingreso a deleteAccount");
    FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
    final FirebaseUser currentUser = firebaseAuth.getCurrentUser();
    currentUser.delete().addOnCompleteListener(new OnCompleteListener<Void>() {
        @Override
        public void onComplete(@NonNull Task<Void> task) {
            if (task.isSuccessful()) {
                Log.d(TAG,"OK! Works fine!");
                startActivity(new Intent(Main3WelcomeActivity.this, Main3Activity.class));
                finish();
            } else {
                Log.w(TAG,"Something is wrong!");
            }
        }
    });
}

Answer 5

使用这种方法： -

去掉（）

相当于调用set(null)。

要么

removeUser（）

removeUser(credentials, [onComplete])

Answer 6

@Android开发者：

我遇到了卸载应用程序后Firebase Auth信息持久存储在设备磁盘中的问题。经过实验和阅读后，我发现在Manifest的android:allowBackup="false"标签中设置android:fullBackupContent="false"和<application>将确保在卸载应用程序后不会保留身份信息。

请注意，所有Android设备上都没有发生这种持久性。事实上，它开始发生在我的一个从未遇到过这个问题的设备上。

Answer 7

只有获取当前用户并使用以下方法删除它才能正常工作

user.delete();

你可以通过addinduser.delete().addOnCompleteListner(new OnCompleteListner)and添加Oncompletelistner