안드로이드) 파이어베이스 구글 로그인

build.gradle (Module 단위)

implementation 'com.google.firebase:firebase-analytics:17.2.2' // 파이어베이스 앱 분석
implementation 'com.google.firebase:firebase-core:17.2.1' // 파이어베이스 코어
implementation 'com.google.firebase:firebase-auth:19.1.0' // 파이어베이스 인증
implementation 'com.firebaseui:firebase-ui-auth:4.2.1' // 파이어베이스 인증2
implementation 'com.github.bumptech.glide:glide:4.9.0' // 글라이드 이미지 로딩
annotationProcessor 'com.github.bumptech.glide:compiler:4.9.0' // 글라이드 이미지 로딩2

 

activity_main.xml (구글 로그인 버튼)

<com.google.android.gms.common.SignInButton 
android:id="@+id/btn_google" 
android:layout_width="200dp"
android:layout_height="wrap_content" />

 

activity_result_login.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".LoginResultActivity">

    <TextView
        android:id="@+id/tv_nickname"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:text="닉네임"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/iv_profile" />

    <ImageView
        android:id="@+id/iv_profile"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginTop="200dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@mipmap/ic_launcher" />
</androidx.constraintlayout.widget.ConstraintLayout>

 

MainActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

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.GoogleAuthProvider;

public class MainActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener {

    private SignInButton btn_google; // 구글 로그인 버튼
    private FirebaseAuth auth;  // Firebase 인증 객체
    private GoogleApiClient googleApiClient; // 구글 api 클라이언트 객체
    private static final int REQ_SIGN_GOOGLE = 100; // 구글 로그인 결과 코드

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

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

        googleApiClient = new GoogleApiClient.Builder(this)
                .enableAutoManage(this,this)
                .addApi(Auth.GOOGLE_SIGN_IN_API, googleSignInOptions)
                .build();

        auth = FirebaseAuth.getInstance(); // Firebase 인증 객체 초기화

        btn_google = findViewById(R.id.btn_google);
        btn_google.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = Auth.GoogleSignInApi.getSignInIntent(googleApiClient);
                startActivityForResult(intent, REQ_SIGN_GOOGLE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if(requestCode == REQ_SIGN_GOOGLE){
            GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
            if(result.isSuccess()){ // 인증 결과가 성공
                GoogleSignInAccount account = result.getSignInAccount(); // 구글 로그인 정보
                resultLoogin(account);
            }
        }
    }

    private void resultLoogin(final GoogleSignInAccount account) {
        AuthCredential credential = GoogleAuthProvider.getCredential(account.getIdToken(), null);
        auth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if(task.isSuccessful()){
                        Toast.makeText(MainActivity.this, "로그인 성공", Toast.LENGTH_SHORT).show();
                        Intent intent = new Intent(getApplicationContext(), LoginResultActivity.class);
                        intent.putExtra("nickName", account.getDisplayName());
                        intent.putExtra("photoUrl", String.valueOf(account.getPhotoUrl()));

                        startActivity(intent);
                    }else{
                        Toast.makeText(MainActivity.this, "로그인 실패", Toast.LENGTH_SHORT).show();
                    }
                }
            });
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
    }
}

 

LoginResultActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

import com.bumptech.glide.Glide;

public class LoginResultActivity extends AppCompatActivity {

    private TextView tv_nickname;
    private ImageView iv_profile;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login_result);

        Intent intent = getIntent();

        tv_nickname = findViewById(R.id.tv_nickname);
        tv_nickname.setText(intent.getStringExtra("nicmName"));

        iv_profile = findViewById(R.id.iv_profile);
        Glide.with(this).load(intent.getStringExtra("photoUrl")).into(iv_profile); // 프로필 url을 이미지에 셋팅

    }
}