[#13][안드로이드] Firebase로 Google 로그인/로그아웃 구현

Firebase로 Google 로그인/로그아웃 구현

public class LoginActivity extends AppCompatActivity implements GoogleApiClient.OnConnectionFailedListener{     private FirebaseAuth mAuth;     private static final int RC_SIGN_IN = 9001;     private GoogleApiClient mGoogleApiClient;     @Override     public void onStart() {         super.onStart();         // 활동을 초기화할 때 사용자가 현재 로그인되어 있는지 확인합니다.         FirebaseUser currentUser = mAuth.getCurrentUser();     }     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_login);         // GoogleSignInOptions 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, this )                 .addApi(Auth.GOOGLE_SIGN_IN_API, gso)                 .build();                      // 로그인 작업의 onCreate 메소드에서 FirebaseAuth 개체의 공유 인스턴스를 가져옵니다.         mAuth = FirebaseAuth.getInstance();         // 로그인 버튼 이벤트 > signInIntent 호출         Button login_btn_google= (Button) findViewById(R.id.login_google);         login_btn_google.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 Log.v("알림", "구글 LOGIN");                 Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(mGoogleApiClient);                 startActivityForResult(signInIntent, RC_SIGN_IN);             }         });         // 로그아웃 버튼 클릭 이벤트 > dialog 예/아니오         Button logout_btn_google = (Button) findViewById(R.id.logout_google);         logout_btn_google.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(final View view) {                 Log.v("알림", "구글 LOGOUT");                 AlertDialog.Builder alt_bld = new AlertDialog.Builder(view.getContext());                 alt_bld.setMessage("로그아웃 하시겠습니까?").setCancelable(false)                         .setPositiveButton("네",                         new DialogInterface.OnClickListener() {                             public void onClick(DialogInterface dialog, int id) {                                 // 네 클릭                                 // 로그아웃 함수 call                                 signOut();  }                         }).setNegativeButton("아니오",                         new DialogInterface.OnClickListener() {                             public void onClick(DialogInterface dialog, int id) {                                 // 아니오 클릭. dialog 닫기.                                 dialog.cancel();                             }                         });                 AlertDialog alert = alt_bld.create();                 // 대화창 클릭시 뒷 배경 어두워지는 것 막기                 //alert.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND);                 // 대화창 제목 설정                 alert.setTitle("로그아웃");                 // 대화창 아이콘 설정                 alert.setIcon(R.drawable.check_dialog_64);                 // 대화창 배경 색 설정                 alert.getWindow().setBackgroundDrawable(new ColorDrawable(Color.argb(255,62,79,92)));                 alert.show();             }         });     }     @Override     protected void onActivityResult(int requestCode, int resultCode, Intent data) {         super.onActivityResult(requestCode, resultCode, data);         if (requestCode == RC_SIGN_IN) {             GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);             if (result.isSuccess()) {                 // Google Sign In was successful, authenticate with Firebase                 Log.v("알림", "google sign 성공, FireBase Auth.");                 GoogleSignInAccount account = result.getSignInAccount();                 firebaseAuthWithGoogle(account);                 Intent intent = new Intent(getApplicationContext(), MainActivity.class);                 startActivity(intent);             } else {                 // Google Sign In failed, update UI appropriately                 Log.v("알림", result.isSuccess() +" Google Sign In failed. Because : " + result.getStatus().toString());                 // ...             }         }     }     // 사용자가 정상적으로 로그인한 후에 GoogleSignInAccount 개체에서 ID 토큰을 가져와서      //Firebase 사용자 인증 정보로 교환하고 Firebase 사용자 인증 정보를 사용해 Firebase에 인증합니다.     private void firebaseAuthWithGoogle(GoogleSignInAccount acct){         AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);         mAuth.signInWithCredential(credential)                 .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {                     @Override                     public void onComplete(@NonNull Task<AuthResult> task) {                         Log.v("알림", "ONCOMPLETE");                         // If sign in fails, display a message to the user. If sign in succeeds                         // the auth state listener will be notified and logic to handle the                         // signed in user can be handled in the listener.                         if (!task.isSuccessful()) {                             Log.v("알림", "!task.isSuccessful()");                             Toast.makeText(LoginActivity.this, "인증에 실패하였습니다.", Toast.LENGTH_SHORT).show();                         }else {                             Log.v("알림", "task.isSuccessful()");                             FirebaseUser user = mAuth.getCurrentUser();                             Toast.makeText(LoginActivity.this, "FireBase 아이디 생성이 완료 되었습니다", Toast.LENGTH_SHORT).show();                         }                     }                 });     }     @Override     public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {         Log.v("알림", "onConnectionFailed");     }     // 로그아웃     public void signOut() {         mGoogleApiClient.connect();         mGoogleApiClient.registerConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() {             @Override             public void onConnected(@Nullable Bundle bundle) {                 mAuth.signOut();                 if (mGoogleApiClient.isConnected()) {                     Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(new ResultCallback<Status>() {                         @Override                         public void onResult(@NonNull Status status) {                             if (status.isSuccess()) {                                 Log.v("알림", "로그아웃 성공");                                 setResult(1);                             } else {                                 setResult(0);                             }                             finish();                         }                     });                 }             }             @Override             public void onConnectionSuspended(int i) {                 Log.v("알림", "Google API Client Connection Suspended");                 setResult(-1);                 finish();             }         });     } } Colored by Color Scripter

cs

결과물
로그아웃 함수 -> finish() -> 로그인 시도 시 로그인 할 구글계정 선택 가능