如何确定用户之前是否已使用google firebase登录登录

Question

我正在使用谷歌登录我的Android项目，并在使用firebase auth成功验证后，我将其他默认字段的用户记录添加到firestore。

问题是当同一用户尝试使用相同的电子邮件再次登录时，同一用户的新文档将添加到firestore数据库（两个文档具有相同的数据）

我需要一种方法来了解用户以前是否已登录，以便我不会将新文档添加到firestore

我搜索了Stack overflow并且只使用电子邮件和密码找到了auth的解决方案。解决方案使用：

authResultTask.getException（）instanceof FirebaseAuthUserCollisionException

这对谷歌登录无效

//google signin result intent
@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == RequestSignInCode){

            GoogleSignInResult googleSignInResult = Auth.GoogleSignInApi.getSignInResultFromIntent(data);

            if (googleSignInResult.isSuccess()){

                Toast.makeText(WelcomeActivity.this,"Google Sign In result available ..."/* authCredential.getProvider()*/,
                        Toast.LENGTH_LONG).show();


                GoogleSignInAccount googleSignInAccount = googleSignInResult.getSignInAccount();

                firebaseUserAuth(googleSignInAccount);
            }
            //else Toast.makeText(this, "falsa1", Toast.LENGTH_SHORT).show();

        }
        //else Toast.makeText(this, "falsa2", Toast.LENGTH_SHORT).show();
    }

    public void firebaseUserAuth(final GoogleSignInAccount googleSignInAccount) {

            AuthCredential authCredential = GoogleAuthProvider.getCredential(googleSignInAccount.getIdToken(), null);

            mAuth.signInWithCredential(authCredential)
                    .addOnCompleteListener(WelcomeActivity.this, new OnCompleteListener<AuthResult>() {
                        @Override
                        public void onComplete(@NonNull Task AuthResultTask) {
                            Log.d("auth", "AuthResultTask:Complete ");

                                if (AuthResultTask.isSuccessful()) {
                                    Log.d("auth", "AuthResultTask successful");

                                    String email = googleSignInAccount.getEmail();

                                    Map<String, Object> userProperties = new HashMap<>();
                                    userProperties.put("email", email);
                                    userProperties.put("fullname", "");
                                    userProperties.put("isActivated", false);
                                    userProperties.put("has_rated", false);
                                    userProperties.put("product_key", "");
                                    userProperties.put("time_registered", new Date());
                                    userProperties.put("total_referral_count", 0);



                                    db.collection("users")
                                            .add(userProperties)
                                            .addOnSuccessListener(new OnSuccessListener<DocumentReference>() {
                                                @Override
                                                public void onSuccess(DocumentReference documentReference) {
                                                    progressBar.setVisibility(View.GONE);
                                                    Log.d("doc_id", documentReference.getId());
                                                    Toast.makeText(WelcomeActivity.this, "Google Sign In successful...",
                                                            Toast.LENGTH_LONG).show();

                                                    startActivity(new Intent(WelcomeActivity.this, MainActivity.class));
                                                }
                                            })
                                            .addOnFailureListener(new OnFailureListener() {
                                                @Override
                                                public void onFailure(@NonNull Exception e) {
                                                    Log.w(DB_TAG, "Error adding document", e);
                                                    progressBar.setVisibility(View.GONE);
                                                }

                                            });


                                } else {
                                    Log.d("auth", "Exception: " + AuthResultTask.getException().toString());
                                    Toast.makeText(WelcomeActivity.this, "Something Went Wrong ...", Toast.LENGTH_LONG).show();
                                    progressBar.setVisibility(View.GONE);
                                }
                            }

                    });
        }

Answer 1

如果您使用由Firebase身份验证分配的用户的UID作为文档的ID而不是使用add()方法创建的随机ID，那么对您来说会更容易。每次用户登录时，UID都是相同的。

AuthResult authResult = ...
FirebaseUser user = authResult.getUser();
// this is unique for the user
String uid = user.getUid();

// Create a document for this user using their UID
db.collection("users").document(uid).set(userProperties);

在尝试像这样写入文档之前，您可能还想检查文档是否已经存在，或者使用合并集来覆盖其现有内容。

Answer 2

据我所知，您正在尝试在用户首次注册时创建文档。因此，您必须在用户注册后提交文档。每次登录后都没有。