Firebase Authentication - 구글 로그인

Firebase 에서 구글 인증으로 로그인 처리하는 방법에 대한 사항이다.

1. https://console.firebase.google.com/ 에 접속한다.

  

   프로젝트가 없으면 추가하고 있으면 선택한다.

2. 앱을 설정하는 일련의 과정은 그림으로 대신한다.

패키지명을 복사하여 붙여넣기 한다.

SHA-1 코드를 알아내는 방법이다.

이제 구성 파일을 다운로드 하여 app 수준의 폴더에 붙여넣기 한다.

인증 활성화 확인 방법

3. 앱 build.gradle 파일 내용

apply plugin: 'com.android.application' android {     compileSdkVersion 29     buildToolsVersion "29.0.2"     defaultConfig {         applicationId "com.link2me.android.googleauth"         minSdkVersion 21         targetSdkVersion 29         versionCode 1         versionName "1.0"     }     buildTypes {         release {             minifyEnabled false             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'         }     } } dependencies {     implementation fileTree(dir: 'libs', include: ['*.jar'])     implementation 'androidx.appcompat:appcompat:1.1.0'     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'     implementation 'com.google.firebase:firebase-analytics:17.2.0'     implementation 'com.google.firebase:firebase-auth:19.1.0'  // Firebase 인증에 대한 항목을 추가     implementation 'com.google.android.gms:play-services-auth:17.0.0' } apply plugin: 'com.google.gms.google-services'

4. XML Layout 작성

<RelativeLayout  xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/main_layout"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:orientation="vertical"     android:gravity="center" >     <!-- 구글 로그인 버튼 -->     <com.google.android.gms.common.SignInButton         android:id="@+id/sign_in_button"         android:layout_width="254dp"         android:layout_height="50sp">     </com.google.android.gms.common.SignInButton>     <ImageView         android:id="@+id/sign_out_button"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignParentLeft="true"         android:layout_alignParentStart="true"         android:layout_below="@+id/sign_in_button"         android:background="@drawable/google_signout"/>     <TextView         android:id="@+id/mStatusTextView"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_alignParentLeft="true"         android:layout_alignParentStart="true"         android:layout_below="@+id/sign_in_button"         android:layout_marginTop="99dp"         android:text="TextView" /> </RelativeLayout >

5. 사용자 인증 코드 작성

https://firebase.google.com/docs/auth/android/google-signin?authuser=0 에서 필요한 코드를 복사하여 붙여넣기 한다.

import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.TextView; import android.widget.Toast; 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.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; public class GoogleSignInActivity extends AppCompatActivity implements View.OnClickListener {     private static final String TAG = "GoogleActivity";     private static final int RC_SIGN_IN = 9001;     private FirebaseAuth mAuth;     private GoogleSignInClient mGoogleSignInClient;     private TextView mStatusTextView;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_google);         // Button listeners         findViewById(R.id.sign_in_button).setOnClickListener(this);         findViewById(R.id.sign_out_button).setOnClickListener(this);         mStatusTextView = findViewById(R.id.mStatusTextView);         // 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);         // Initialize Firebase Auth         mAuth = FirebaseAuth.getInstance();     }     @Override     public void onClick(View view) {         switch (view.getId()) {             case R.id.sign_in_button:                 signIn(); // 구글 로그인 버튼 클릭시                 break;             case R.id.sign_out_button:                 signOut();                 break;         }     }     @Override     public void onStart() {         super.onStart();         // Check if user is signed in (non-null) and update UI accordingly.         FirebaseUser currentUser = mAuth.getCurrentUser();         updateUI(currentUser);     }     @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) {                 Log.w(TAG, "Google sign in failed", e);                 updateUI(null);             }         }     }     private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {         Log.d(TAG, "firebaseAuthWithGoogle:" + 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) {                         if (task.isSuccessful()) {                             // Sign in success, update UI with the signed-in user's information                             Log.e(TAG, "signInWithCredential:success");                             FirebaseUser user = mAuth.getCurrentUser();                             updateUI(user);                             Log.e(TAG,"user getEmail : "+user.getEmail());                             Log.e(TAG,"user getDisplayName : "+user.getDisplayName());                             Log.e(TAG,"user getUid : "+user.getUid());                         } else {                             // If sign in fails, display a message to the user.                             Log.w(TAG, "signInWithCredential:failure", task.getException());                             Toast.makeText(GoogleSignInActivity.this, "Authentication Failed.", Toast.LENGTH_SHORT).show();                             updateUI(null);                         }                         // [START_EXCLUDE]                         //hideProgressDialog();                         // [END_EXCLUDE]                     }                 });     }     private void signIn() {         Intent signInIntent = mGoogleSignInClient.getSignInIntent();         startActivityForResult(signInIntent, RC_SIGN_IN);     }     private void signOut() {         mAuth.signOut(); // Firebase sign out         // Google sign out         mGoogleSignInClient.signOut().addOnCompleteListener(this,                 new OnCompleteListener<Void>() {                     @Override                     public void onComplete(@NonNull Task<Void> task) {                         updateUI(null);                     }                 });     }     private void revokeAccess() {         // Firebase sign out         mAuth.signOut();         // Google revoke access         mGoogleSignInClient.revokeAccess().addOnCompleteListener(this,                 new OnCompleteListener<Void>() {                     @Override                     public void onComplete(@NonNull Task<Void> task) {                         updateUI(null);                     }                 });     }     private void updateUI(FirebaseUser user) {         //hideProgressDialog();         if (user != null) {             mStatusTextView.setText(user.getEmail() + " : " + user.getDisplayName());             findViewById(R.id.sign_in_button).setVisibility(View.GONE);             findViewById(R.id.sign_out_button).setVisibility(View.VISIBLE);         } else {             mStatusTextView.setText("LogOut");             findViewById(R.id.sign_in_button).setVisibility(View.VISIBLE);             findViewById(R.id.sign_out_button).setVisibility(View.GONE);         }     }     @Override     protected void onDestroy() {         super.onDestroy();         //FirebaseAuth.getInstance().signOut();     } }

6. 로그인 후 Firebase 에 회원정보 저장 결과