[FIXED] how to get the firebase UID of the user who logged in via google?

Issue

I'm trying to get UID of user who signed in via google.

When I'm using FirebaseAuth.getInstance().getCurrentUser().getUid() its obviously shows error.

When I'm using GoogleSignIn.getLastSignedInAccount(getContext()).getId its show incorrect ID .

How could I get this his UID?

There is code that I used to sign in via google. I get it from https://firebase.google.com/docs/auth/android/google-signin

signInOptions = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
            .requestIdToken("R.string.default_client_id")
            .requestEmail()
            .build();

    signInClient = GoogleSignIn.getClient(this, signInOptions);

    signIn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent sign = signInClient.getSignInIntent();
            startActivityForResult(sign, GOOGLE_SIGN_IN_CODE);
        }
    });

 @Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if(requestCode == GOOGLE_SIGN_IN_CODE){
        Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
        try {
            // Google Sign In was successful, authenticate with Firebase
            GoogleSignInAccount account = task.getResult(ApiException.class);
            System.out.println("firebaseAuthWithGoogle:" + account.getId());
            firebaseAuthWithGoogle( account.getIdToken());
        } catch (ApiException e) {
            // Google Sign In failed, update UI appropriately
        }
    }
}
private void firebaseAuthWithGoogle(String idToken) {
    AuthCredential credential = GoogleAuthProvider.getCredential(idToken, null);
    mAuth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        FirebaseUser user = mAuth.getCurrentUser();
                        startActivity(new Intent(MainActivity.this,NavActivity.class));
                        updateUI(user);
                    } else {
                        updateUI(null);
                    }
                }
            });
}

This is how I get the UID

String uid = "";
    if(firebaseUser!=null ){
        uid = firebaseUser.getUid();
    }

Solution

You need to use your google sign-in token to log into Firebase.

FirebaseAuth.getInstance().signInWithCredential(GoogleAuthProvider.getCredential(googleSignInAccount.getIdToken(), null))

Because your FirebaseUser and your Google account are using two different authorizations, therefore can't be used interchangeably.

Answered By - Abdullah Z Khan

Answer Checked By - Pedro (PHPFixing Volunteer)