如何检测已存储到数据库的Google登录帐户?

Question

我正在创建支持电子邮件和谷歌登录身份验证和Firebase数据库的用户应用程序。每次我第一次使用Google帐户签名时，帐户数据都会作为新用户记录存储在Firebase数据库中。但是，当我注销并使用以前的同一Google帐户登录时，我发现问题。我怎样才能知道 Google 帐户已注册并存储到 Firebase，即使已注销？。我的逻辑是，当用户第一次使用Google帐户登录时，帐户数据将存储到Firebase数据库中，应用程序将检测到该帐户是否已注册并存储到数据库中。

有与我的问题相关的LoginActivity.java类和ProfilActivity.java类的代码。

登录活动.java类

package co.id.roni.usertestapp;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.util.Patterns;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class LoginUserActivity extends AppCompatActivity implements View.OnClickListener {
private static final int RC_SIGN_IN = 1001;
private static final String TAG = "Google Activity";
TextView tvDaftarLinkPage;
Button SignIn;
FirebaseAuth signInAuth;
FirebaseUser signInAuthUser;
EditText emailSignIn, passSignIn;
SignInButton googleSignInButton;
DatabaseReference reference;
boolean isGoogleSignIn;
GoogleSignInClient mGoogleSignInClient;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_user);
SignIn = findViewById(R.id.btn_sign_in);
tvDaftarLinkPage = findViewById(R.id.tv_register_link_text);
emailSignIn = findViewById(R.id.edt_email_signin);
passSignIn = findViewById(R.id.edt_pass_signin);
googleSignInButton = findViewById(R.id.btn_sign_in_google);
googleSignInButton.setOnClickListener(this);
signInAuth = FirebaseAuth.getInstance();
signInAuthUser = signInAuth.getCurrentUser();
tvDaftarLinkPage.setOnClickListener(this);
SignIn.setOnClickListener(this);
reference = FirebaseDatabase.getInstance().getReference("Users");
// Configure Google Sign In
GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestIdToken(getString(R.string.default_web_client_id))
.requestEmail()
.build();
mGoogleSignInClient = GoogleSignIn.getClient(this, gso);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.tv_register_link_text:
startActivity(new Intent(LoginUserActivity.this, RegisterUserActivity.class));
finish();
break;
case R.id.btn_sign_in:
signInProcess();
break;
case R.id.btn_sign_in_google:
signInWithGoogle();
break;
}
}
//    sign In with Google
private void signInWithGoogle() {
Intent signInIntent = mGoogleSignInClient.getSignInIntent();
startActivityForResult(signInIntent, RC_SIGN_IN);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
if (requestCode == RC_SIGN_IN) {
Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
try {
// Google Sign In was successful, authenticate with Firebase
GoogleSignInAccount account = task.getResult(ApiException.class);
firebaseAuthWithGoogle(account);
} catch (ApiException e) {
// Google Sign In failed, update UI appropriately
Log.w(TAG, "Google sign in failed", e);
// [START_EXCLUDE]
//                updateUI(null);
// [END_EXCLUDE]
}
}
}
//process google account sign in
private void firebaseAuthWithGoogle(final GoogleSignInAccount account) {
Log.d(TAG, "firebaseAuthWithGoogle:" + account.getId());
AuthCredential credential = GoogleAuthProvider.getCredential(account.getIdToken(), null);
signInAuth.signInWithCredential(credential)
.addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
// Sign in success, update UI with the signed-in user's information
Log.d(TAG, "signInWithCredential:success");
//variabel isGoogleSignIn is used for checking sign in google
isGoogleSignIn = true;
FirebaseUser user = signInAuth.getCurrentUser();
//the problem code is here! How I can detect the google user account has stored and registered 
if (user != null) {
String uid = user.getUid();
reference.child(uid).child("uid").setValue(uid);
reference.child(uid).child("name").setValue(user.getDisplayName());
reference.child(uid).child("email").setValue(user.getEmail());
reference.child(uid).child("photo").setValue(String.valueOf(user.getPhotoUrl()));

}
startActivity(new Intent(LoginUserActivity.this, ProfilUserActivity.class));
finish();
} else {
// If sign in fails, display a message to the user.
Log.w(TAG, "signInWithCredential:failure", task.getException());
}
// [START_EXCLUDE]
//                        hideProgressDialog();
// [END_EXCLUDE]
}
});
}
//this method for login with email. this is success
private void signInProcess() {
final String email = emailSignIn.getText().toString();
final String pass = passSignIn.getText().toString();
if (email.isEmpty()) {
emailSignIn.setError("Tidak boleh kosong");
} else if (!Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
emailSignIn.setError("Email tidak valid");
} else if (pass.isEmpty()) {
passSignIn.setError("Password tidak boleh kosong");
} else if (pass.length() <= 6) {
passSignIn.setError("Password minimal 6 karakter");
} else {
signInAuth.signInWithEmailAndPassword(email, pass).addOnCompleteListener(LoginUserActivity.this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if (task.isSuccessful()) {
startActivity(new Intent(LoginUserActivity.this, ProfilUserActivity.class));
finish();
} else {
Log.e("Pesan", "Gagal Sign In : " + task.getException());
}
}
});
}
}
}
```

ProfilActivity.java类

package co.id.roni.usertestapp;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.squareup.picasso.Picasso;
public class ProfilUserActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener, View.OnClickListener {
TextView namaProfile, emailProfile;
ImageView photoImageProfile;
FirebaseAuth firebaseAuthMain;
FirebaseUser user;
DatabaseReference profileDb;
GoogleSignInClient googleSignInClient;
boolean isGoogleSignIn;
private static final String TAG ="Pesan" ;
GoogleSignInOptions gso;

private GoogleApiClient mGoogleApiClient;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profil_user);
Button btnEditProfile = findViewById(R.id.btn_edit_profile);
Button btnSignOut = findViewById(R.id.btn_sign_out);
namaProfile = findViewById(R.id.tv_nama_profil);
emailProfile = findViewById(R.id.tv_email_profil_page);
photoImageProfile = findViewById(R.id.img_profile_page);
firebaseAuthMain = FirebaseAuth.getInstance();
user = firebaseAuthMain.getCurrentUser();
if(user != null){
showProfile();
}
btnEditProfile.setOnClickListener(this);
gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
.requestEmail()
.build();
mGoogleApiClient = new GoogleApiClient.Builder(this)
.enableAutoManage(this, this)
.addApi(Auth.GOOGLE_SIGN_IN_API,gso)
.build();
btnSignOut.setOnClickListener(this);
}
private void showProfile() {
profileDb = FirebaseDatabase.getInstance().getReference().child("Users").child(user.getUid());
profileDb.getRef().addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
emailProfile.setText(dataSnapshot.child("email").getValue().toString());
namaProfile.setText(dataSnapshot.child("name").getValue().toString());
Picasso.get().load(dataSnapshot.child("photo").getValue().toString()).centerCrop().fit().into(photoImageProfile);
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
Log.e("Pesan", "Gagal Load"+databaseError.getMessage());
}
});
}
@Override
public void onClick(View view) {
if(view.getId() == R.id.btn_edit_profile){
startActivity(new Intent(ProfilUserActivity.this, EditProfileActivity.class));
finish();
}
if(view.getId() == R.id.btn_sign_out){
if(user != null){
firebaseAuthMain.signOut();
//every sign out, user can choose another gmail but the problem is how to know the gmail has registered
Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(new ResultCallback<Status>() {
@Override
public void onResult(@NonNull Status status) {
startActivity(new Intent(ProfilUserActivity.this, UserMainActivity.class));
finish();
}
});
//                goog.signOut().addOnCompleteListener(this, new OnCompleteListener<Void>() {
//                    @Override
//                    public void onComplete(@NonNull Task<Void> task) {
//
//                    }
//                });
}
else{
Log.e("Status", "Gagal Keluar");
}

}
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
Log.e(TAG, "message"+connectionResult.getErrorMessage());
}
}

我希望应用程序可以检测到哪些gmail帐户已注册并存储到Firebase数据库，以便个人资料页面仅显示数据库中的数据

Answer 1

将代码替换为以下代码。由于它会检查用户是否不为空并将执行代码，直到它达到启动活动功能，您的所有Google数据都将存储在Firebase中。如果未发送数据，则可能无法启动活动。

if (user != null) {
String uid = user.getUid();
reference.child(uid).child("uid").setValue(uid);
reference.child(uid).child("name").setValue(user.getDisplayName());
reference.child(uid).child("email").setValue(user.getEmail());
reference.child(uid).child("photo").setValue(String.valueOf(user.getPhotoUrl()));
startActivity(new Intent(LoginUserActivity.this, ProfilUserActivity.class));
finish();
}