Inicio de sesión con Facebook para Android: inicio rápido

<com.facebook.login.widget.LoginButton
    android:id="@+id/login_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:layout_marginTop="30dp"
    android:layout_marginBottom="30dp" /> 

callbackManager = CallbackManager.Factory.create();

      
    private static final String EMAIL = "email";
      
    loginButton = (LoginButton) findViewById(R.id.login_button);
    loginButton.setReadPermissions(Arrays.asList(EMAIL));
    // If you are using in a fragment, call loginButton.setFragment(this);    

    // Callback registration
    loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
        @Override
        public void onSuccess(LoginResult loginResult) {
            // App code
        }

        @Override
        public void onCancel() {
            // App code
        }

        @Override
        public void onError(FacebookException exception) {
            // App code
        }
    });

    callbackManager = CallbackManager.Factory.create();      
      
    LoginManager.getInstance().registerCallback(callbackManager,
            new FacebookCallback<LoginResult>() {
                @Override
                public void onSuccess(LoginResult loginResult) {
                    // App code
                }

                @Override
                public void onCancel() {
                     // App code
                }

                @Override
                public void onError(FacebookException exception) {
                     // App code   
                }
    });

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

AccessToken accessToken = AccessToken.getCurrentAccessToken();
boolean isLoggedIn = accessToken != null && !accessToken.isExpired();
  

      
LoginManager.getInstance().logInWithReadPermissions(this, Arrays.asList("public_profile"));

  
<queries>
  <package android:name="com.facebook.katana" />
</queries> 
  

LoginManager.getInstance().retrieveLoginStatus(this, new LoginStatusCallback() {
    @Override
    public void onCompleted(AccessToken accessToken) {
        // User was previously logged in, can log them in directly here.
        // If this callback is called, a popup notification appears that says
        // "Logged in as <User Name>"
    }
    @Override
    public void onFailure() {
        // No access token could be retrieved for the user
    }
    @Override
    public void onError(Exception exception) {
        // An error occurred
    }
});