firebase Authentication과 구글 로그인 연동

1.

모듈 app gradle에 인증에 대한 항목을 추가해준다.

현재 최신 버전은 11.2.0이다.

compile 'com.google.firebase:firebase-auth:10.0.1'
compile 'com.google.android.gms:play-services-auth:10.0.1'

2.

로그인을 시도 할 엑티비티에서 유저 데이터를 요청한다.

GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
        .requestIdToken(getString(R.string.default_web_client_id))
        .requestEmail()
        .build();

3.

버튼 생성 SignInButton 이라고 구글에서 지원하는 버튼이 있다. 물론 커스텀 버튼 사용해도 됨.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.google.android.gms.common.SignInButton
        android:id="@+id/google_login_button"
        android:layout_width="300dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="122dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"></com.google.android.gms.common.SignInButton>
    

</RelativeLayout>

4.

버튼 리스너 설정

signInButton = (SignInButton)findViewById(R.id.google_login_button);

signInButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }
});

5.

로그인 Result를 받을 메서드. onActivityResult에서 정보를 받고 firebaseAuthWithGoogle에서 인증한다. 인증이 성공하면 메인엑티비티로 넘어간다.

@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) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        if (result.isSuccess()) {
            // Google Sign In was successful, authenticate with Firebase
            GoogleSignInAccount account = result.getSignInAccount();

            Log.d(TAG, "이름 =" + account.getDisplayName());
            Log.d(TAG, "이메일=" + account.getEmail());
            Log.d(TAG, "getId()=" + account.getId());
            Log.d(TAG, "getAccount()=" + account.getAccount());
            Log.d(TAG, "getIdToken()=" + account.getIdToken());
            firebaseAuthWithGoogle(account);
        } else {
            // Google Sign In failed, update UI appropriately
            // ...
        }
    }
}

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
                        Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                        startActivity(intent);
                        finish();
                        Log.d(TAG, "signInWithCredential:success");
                    } else {
                        // If sign in fails, display a message to the user.
                        Log.w(TAG, "signInWithCredential:failure", task.getException());
                        Toast.makeText(LoginActivity.this, "Authentication failed.",
                                Toast.LENGTH_SHORT).show();
                    }

                    // ...
                }
            });
}

항상 로그인 화면이 아닐테니까, 로그인 후 앱 사용 할 시에는 로그인 뷰를 보여주지 않는다.

public void onStart() { // 사용자가 현재 로그인되어 있는지 확인
    super.onStart();
    // Check if user is signed in (non-null) and update UI accordingly.
    FirebaseUser currentUser = mAuth.getCurrentUser();
    if(currentUser!=null){ // 만약 로그인이 되어있으면 다음 액티비티 실행
        Intent intent = new Intent(getApplicationContext(), MainActivity.class);
        startActivity(intent);
        finish();
    }
}

전체코드 

접기

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.auth.api.signin.GoogleSignInResult;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.GoogleApiClient;
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 static android.content.ContentValues.TAG;

/**
 * Created by user on 2017-11-04.
 */

public class LoginActivity extends AppCompatActivity {
    final int RC_SIGN_IN = 1001; // 로그인 확인여부 코드
    private FirebaseAuth mAuth;
    private SignInButton signInButton; //구글 로그인 버튼
    private GoogleApiClient mGoogleApiClient; //API 클라이언트
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        mAuth = FirebaseAuth.getInstance(); // 인스턴스 생성

        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this, new GoogleApiClient.OnConnectionFailedListener() {
                    @Override
                    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

                    }
                })
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();

        signInButton = (SignInButton)findViewById(R.id.google_login_button);

        signInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);
                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) {
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            if (result.isSuccess()) {
                // Google Sign In was successful, authenticate with Firebase
                GoogleSignInAccount account = result.getSignInAccount();

                Log.d(TAG, "이름 =" + account.getDisplayName());
                Log.d(TAG, "이메일=" + account.getEmail());
                Log.d(TAG, "getId()=" + account.getId());
                Log.d(TAG, "getAccount()=" + account.getAccount());
                Log.d(TAG, "getIdToken()=" + account.getIdToken());
                firebaseAuthWithGoogle(account);
            } else {
                // Google Sign In failed, update UI appropriately
                // ...
            }
        }
    }

    public void onStart() { // 사용자가 현재 로그인되어 있는지 확인
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
        if(currentUser!=null){ // 만약 로그인이 되어있으면 다음 액티비티 실행
            Intent intent = new Intent(getApplicationContext(), MainActivity.class);
            startActivity(intent);
            finish();
        }
    }

    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
                            Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                            startActivity(intent);
                            finish();
                            Log.d(TAG, "signInWithCredential:success");
                        } else {
                            // If sign in fails, display a message to the user.
                            Log.w(TAG, "signInWithCredential:failure", task.getException());
                            Toast.makeText(LoginActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();
                        }

                        // ...
                    }
                });
    }

}

접기

참고 : https://firebase.google.com/docs/auth/android/google-signin?authuser=0

원문출처 : http://cres-cent.tistory.com/8

참고

http://dailyddubby.blogspot.com/2018/03/13-firebase-google.html

http://charactermail.tistory.com/98

http://superwony.tistory.com/2