Android 앱에 Google 로그인을 통합하려면 Google 로그인을 구성하고 로그인 흐름을 시작하는 버튼을 앱의 레이아웃에 추가합니다.
시작하기 전에
Google API 콘솔 프로젝트를 구성하고 Android 스튜디오 프로젝트를 설정합니다.
Google 로그인 및 GoogleSignInClient 객체 구성
로그인 활동의 onCreate 메서드에서 앱에 필요한 사용자 데이터를 요청하도록 Google 로그인을 구성합니다. 예를 들어 사용자의 ID와 기본 프로필 정보를 요청하도록 Google 로그인을 구성하려면 DEFAULT_SIGN_IN 매개변수를 사용하여 GoogleSignInOptions 객체를 만듭니다. 사용자의 이메일 주소도 요청하려면 requestEmail 옵션으로 GoogleSignInOptions 객체를 만드세요.
// Configure sign-in to request the user's ID, email address, and basic// profile. ID and basic profile are included in DEFAULT_SIGN_IN.GoogleSignInOptionsgso=newGoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestEmail().build();
Google API에 액세스하기 위해 추가 범위를 요청해야 하는 경우 requestScopes를 사용하여 지정합니다.
최상의 사용자 환경을 위해 로그인 시 앱이 최소한으로 작동하는 데 필요한 범위만 요청하세요. 사용자가 실행한 작업의 컨텍스트에서 동의 화면이 표시되도록 필요한 경우에만 추가 범위를 요청하세요.
추가 범위 요청을 참고하세요.
그런 다음 로그인 활동의 onCreate 메서드에서 지정한 옵션으로 GoogleSignInClient 객체를 만듭니다.
// Build a GoogleSignInClient with the options specified by gso.mGoogleSignInClient=GoogleSignIn.getClient(this,gso);
기존 로그인 사용자 확인
활동의 onStart 메서드에서 사용자가 이미 Google로 앱에 로그인했는지 확인합니다.
// Check for existing Google Sign In account, if the user is already signed in// the GoogleSignInAccount will be non-null.GoogleSignInAccountaccount=GoogleSignIn.getLastSignedInAccount(this);updateUI(account);
GoogleSignIn.getLastSignedInAccount가 null가 아닌 GoogleSignInAccount 객체를 반환하면 사용자가 이미 Google로 앱에 로그인한 것입니다.
그에 따라 UI를 업데이트합니다. 즉, 로그인 버튼을 숨기거나, 기본 활동을 시작하거나, 앱에 적합한 작업을 실행합니다.
GoogleSignIn.getLastSignedInAccount가 null를 반환하면 사용자가 아직 Google로 앱에 로그인하지 않은 것입니다. Google 로그인 버튼을 표시하도록 UI를 업데이트합니다.
선택사항: 자체 로그인 버튼 애셋을 제공하는 대신 기본 로그인 버튼 그래픽을 사용하는 경우 setSize 메서드를 사용하여 버튼의 크기를 맞춤설정할 수 있습니다.
// Set the dimensions of the sign-in button.SignInButtonsignInButton=findViewById(R.id.sign_in_button);signInButton.setSize(SignInButton.SIZE_STANDARD);
Android 활동 (예: onCreate 메서드)에서 클릭 시 사용자를 로그인하도록 버튼의 OnClickListener를 등록합니다.
getEmail을 사용하여 사용자의 이메일 주소를 가져오고, getId을 사용하여 사용자의 Google ID (클라이언트 측 사용)를 가져오고, getIdToken을 사용하여 사용자의 ID 토큰을 가져올 수도 있습니다.
현재 로그인한 사용자를 백엔드 서버에 전달해야 하는 경우 ID 토큰을 백엔드 서버에 전송하고 서버에서 토큰을 검증합니다.
이 페이지에 나와 있는 콘텐츠와 코드 샘플에는 콘텐츠 라이선스에서 설명하는 라이선스가 적용됩니다. 자바 및 OpenJDK는 Oracle 및 Oracle 계열사의 상표 또는 등록 상표입니다.
최종 업데이트: 2025-07-27(UTC)
[null,null,["최종 업데이트: 2025-07-27(UTC)"],[],[],null,["# Integrate Google Sign-In into Your Android App\n\n| **Warning:**\n|\n| **The Google Sign-In for Android API is outdated and no longer supported.**\n| To ensure the continued security and usability of your app, [migrate your Sign in with\n| Google implementation to Credential Manager](/identity/sign-in/credential-manager-siwg) today. Credential Manager\n| supports passkey, password, and federated identity authentication (such as\n| Sign-in with Google), stronger security, and a more consistent user\n| experience.\n|\n| **For Wear developers:** Credential Manager will be supported in Wear OS\n| 5.1 and later on selected watches. Developers actively supporting Wear OS 3, 4\n| and 5.0 devices with Sign in with Google should continue using Google Sign-in\n| for Android for your Wear applications. Sign in with Google support will be\n| available on Credential Manager APIs for these versions of WearOS at a later\n| date.\n\nTo integrate Google Sign-In into your Android app, configure Google Sign-In and\nadd a button to your app's layout that starts the sign-in flow.\n\nBefore you begin\n----------------\n\nConfigure a Google API Console project and set up your Android Studio project.\n\nConfigure Google Sign-in and the GoogleSignInClient object\n----------------------------------------------------------\n\n1. In your sign-in activity's `onCreate` method, configure Google Sign-In to\n request the user data required by your app. For example, to configure\n Google Sign-In to request users' ID and basic profile information, create a\n [`GoogleSignInOptions`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInOptions.Builder.html#GoogleSignInOptions.Builder())\n object with the `DEFAULT_SIGN_IN` parameter. To request users' email\n addresses as well, create the `GoogleSignInOptions` object with the\n `requestEmail` option.\n\n ```carbon\n // Configure sign-in to request the user's ID, email address, and basic\n // profile. ID and basic profile are included in DEFAULT_SIGN_IN.\n GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)\n .requestEmail()\n .build();\n ```\n\n If you need to request additional scopes to access Google APIs, specify them\n with [`requestScopes`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInOptions.Builder.html#requestScopes(com.google.android.gms.common.api.Scope,%20com.google.android.gms.common.api.Scope...)).\n For the best user experience, on sign-in, only request the scopes that are\n required for your app to minimally function. Request any additional scopes\n only when you need them, so that your users see the consent screen in the\n context of an action they performed.\n See [Requesting Additional Scopes](https://developers.google.com/identity/sign-in/android/additional-scopes).\n2. Then, also in your sign-in activity's `onCreate` method, create a\n `GoogleSignInClient` object with the options you specified.\n\n ```scilab\n // Build a GoogleSignInClient with the options specified by gso.\n mGoogleSignInClient = GoogleSignIn.getClient(this, gso);\n ```\n\nCheck for an existing signed-in user\n------------------------------------\n\nIn your activity's `onStart` method, check if a user has already signed in to\nyour app with Google. \n\n```scilab\n// Check for existing Google Sign In account, if the user is already signed in\n// the GoogleSignInAccount will be non-null.\nGoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(this);\nupdateUI(account);\n```\n\nIf `GoogleSignIn.getLastSignedInAccount` returns a `GoogleSignInAccount` object\n(rather than `null`), the user has already signed in to your app with Google.\nUpdate your UI accordingly---that is, hide the sign-in button, launch your\nmain activity, or whatever is appropriate for your app.\n\nIf `GoogleSignIn.getLastSignedInAccount` returns `null`, the user has not yet\nsigned in to your app with Google. Update your UI to display the Google Sign-in\nbutton.\n| **Note:** If you need to detect changes to a user's auth state that happen outside your app, such as access token or ID token revocation, or to perform cross-device sign-in, you might also call `GoogleSignInClient.silentSignIn` when your app starts.\n\nAdd the Google Sign-in button to your app\n-----------------------------------------\n\n1.\n Add the [`SignInButton`](https://developers.google.com/android/reference/com/google/android/gms/common/SignInButton)\n in your application's layout:\n\n \u003ccom.google.android.gms.common.SignInButton\n android:id=\"@+id/sign_in_button\"\n android:layout_width=\"wrap_content\"\n android:layout_height=\"wrap_content\" /\u003e\n\n2. **Optional** : If you are using the default sign-in button graphic instead of\n providing your own sign-in button assets, you can customize the button's\n size with the [`setSize`](https://developers.google.com/android/reference/com/google/android/gms/common/SignInButton.html#setSize(int))\n method.\n\n ```scilab\n // Set the dimensions of the sign-in button.\n SignInButton signInButton = findViewById(R.id.sign_in_button);\n signInButton.setSize(SignInButton.SIZE_STANDARD);\n ```\n3. In the Android activity (for example, in the `onCreate` method), register\n your button's `OnClickListener` to sign in the user when clicked:\n\n findViewById(R.id.sign_in_button).setOnClickListener(this);\n\nStart the sign-in flow\n----------------------\n\n1.\n In the activity's `onClick` method, handle sign-in button taps by creating a\n sign-in intent with the [`getSignInIntent`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInClient#getSignInIntent())\n method, and starting the intent with `startActivityForResult`.\n\n @Override\n public void onClick(View v) {\n switch (v.getId()) {\n case R.id.sign_in_button:\n signIn();\n break;\n // ...\n }\n }\n\n ```scdoc\n private void signIn() {\n Intent signInIntent = mGoogleSignInClient.getSignInIntent();\n startActivityForResult(signInIntent, RC_SIGN_IN);\n }\n ```\n\n Starting the intent prompts the user to select a Google Account to sign in\n with. If you requested scopes beyond `profile`, `email`, and `openid`, the\n user is also prompted to grant access to the requested resources.\n2. After the user signs in, you can get a [`GoogleSignInAccount`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInAccount.html)\n object for the user in the activity's `onActivityResult` method.\n\n ```transact-sql\n @Override\n public void onActivityResult(int requestCode, int resultCode, Intent data) {\n super.onActivityResult(requestCode, resultCode, data);\n\n // Result returned from launching the Intent from GoogleSignInClient.getSignInIntent(...);\n if (requestCode == RC_SIGN_IN) {\n // The Task returned from this call is always completed, no need to attach\n // a listener.\n Task\u003cGoogleSignInAccount\u003e task = GoogleSignIn.getSignedInAccountFromIntent(data);\n handleSignInResult(task);\n }\n }\n ```\n\n The `GoogleSignInAccount` object contains information about the signed-in\n user, such as the user's name. \n\n ```css+lasso\n private void handleSignInResult(Task\u003cGoogleSignInAccount\u003e completedTask) {\n try {\n GoogleSignInAccount account = completedTask.getResult(ApiException.class);\n\n // Signed in successfully, show authenticated UI.\n updateUI(account);\n } catch (ApiException e) {\n // The ApiException status code indicates the detailed failure reason.\n // Please refer to the GoogleSignInStatusCodes class reference for more information.\n Log.w(TAG, \"signInResult:failed code=\" + e.getStatusCode());\n updateUI(null);\n }\n }\n ```\n\n You can also get the user's email address with [`getEmail`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInAccount.html#getEmail()),\n the user's Google ID (for client-side use) with [`getId`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInAccount.html#getId()),\n and an ID token for the user with [`getIdToken`](https://developers.google.com/android/reference/com/google/android/gms/auth/api/signin/GoogleSignInAccount.html#getIdToken()).\n If you need to pass the currently signed-in user to a backend server,\n [send the ID token to your backend server](https://developers.google.com/identity/sign-in/android/backend-auth)\n and validate the token on the server."]]
애플리케이션의 레이아웃에 
활동의