如何检查用户是否已经通过gmail或google帐户登录？

Question

                if(!em.isEmpty() || !pass.isEmpty()) {
                    mfirebaseAuth.signInWithEmailAndPassword(em, pass).addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                        @Override
                        public void onComplete(@NonNull Task<AuthResult> task) {
                            if (task.isSuccessful()) {
                                    Toast.makeText(getApplicationContext(), "Logged in successfully", Toast.LENGTH_SHORT).show();


                            } else {
                                String errorCode = ((FirebaseAuthException) task.getException()).getErrorCode();

                                switch (errorCode) {

                                    case "ERROR_INVALID_EMAIL":
                                        Toast.makeText(MainLoginActivity.this, "The email address is badly formatted.", Toast.LENGTH_LONG).show();
                                        email.setError("The email address is badly formatted.");
                                        email.requestFocus();
                                        break;


                                    case "ERROR_USER_MISMATCH":
                                        Toast.makeText(MainLoginActivity.this, "The supplied credentials do not correspond to the previously signed in user.", Toast.LENGTH_LONG).show();
                                        break;

                                    case "ERROR_ACCOUNT_EXISTS_WITH_DIFFERENT_CREDENTIAL":
                                        Toast.makeText(MainLoginActivity.this, "An account already exists with the same email address but different sign-in credentials. Sign in using associated email address.", Toast.LENGTH_LONG).show();
                                        break;

                                    case "ERROR_EMAIL_ALREADY_IN_USE":
                                        Toast.makeText(MainLoginActivity.this, "The email address is already in use by another account.", Toast.LENGTH_LONG).show();
                                        email.requestFocus();
                                        break;

                                    case "ERROR_CREDENTIAL_ALREADY_IN_USE":
                                        Toast.makeText(MainLoginActivity.this, "This credential is already associated with a different user account.", Toast.LENGTH_LONG).show();
                                        break;

                                    case "ERROR_USER_DISABLED":
                                        Toast.makeText(MainLoginActivity.this, "The user account has been disabled by an administrator.", Toast.LENGTH_LONG).show();
                                        break;

                                    case "ERROR_INVALID_USER_TOKEN":
                                        Toast.makeText(MainLoginActivity.this, "The user\\'s credential is no longer valid. The user must sign in again.", Toast.LENGTH_LONG).show();
                                        break;

                                    case "ERROR_WRONG_PASSWORD":
                                        Toast.makeText(MainLoginActivity.this, "The password is invalid or the user does not have a password.", Toast.LENGTH_LONG).show();
                                        password.setError("password is incorrect ");
                                        password.requestFocus();
                                        password.setText("");
                                        break;

                                    default:
                                        Toast.makeText(getApplicationContext(), "Error! " + task.getException().getMessage(), Toast.LENGTH_SHORT).show();


                                }
                            }
                        }
                    });
                }

我面临的问题是：

用户首先使用“使用电子邮件注册”进行注册。之后，用户注册了一个谷歌帐户（有相同的电子邮件）。

现在之后，当用户尝试通过电子邮件和密码登录。我得到错误的密码是不正确的，我知道这是因为注册与电子邮件详细信息已经覆盖了谷歌帐户详细信息。

我要显示错误“电子邮件与谷歌帐户链接，请通过谷歌帐户登录”。

Answer 1

您应该使用authCredential和isNewUser这里是示例

 private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d("TAG", "signInWithCredential:success" + acct.getId());

        AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
        mAuth.signInWithCredential(credential).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
        @Override
        public void onComplete(@NonNull Task<AuthResult> task) {
            boolean isNewUser = task.getResult().getAdditionalUserInfo().isNewUser();
            if (isNewUser) {

                Log.d(TAG, "Is New User!");
                FirebaseUser user = mAuth.getCurrentUser();
                //do something
                //You can call register class or function here


            } else {

                Log.d(TAG, "Is Old User!");
                //Do something else


            }
        }

    });

}