OAuth 2.0 for Android Apps

gistfile1.java

/*
 * Copyright 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.accounts.Account;
import android.accounts.AccountManager;
import android.accounts.AccountManagerCallback;
import android.accounts.AccountManagerFuture;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;

/**
 * Collection of OAuth 2 utilities to achieve "one-click" approval on Android.
 *
 * @author Chirag Shah <chirags@google.com>
 */
public class AuthUtils {
  private static final String TAG = AuthUtils.class.getName();

  public static final String PREF_NAME = "Sample App";
  public static final String PREF_TOKEN = "accessToken";
  public static final String SCOPE = "oauth2:https://www.googleapis.com/auth/buzz"; // Or "Google Buzz"

  public void refreshAuthToken(final Activity activity, final Account account) {
    final SharedPreferences settings = activity.getSharedPreferences(PREF_NAME, 0);
    String accessToken = settings.getString(PREF_TOKEN, "");
    final AccountManagerCallback<Bundle> cb = new AccountManagerCallback<Bundle>() {
      public void run(AccountManagerFuture<Bundle> future) {
        try {
          final Bundle result = future.getResult();
          final String accountName = result.getString(AccountManager.KEY_ACCOUNT_NAME);
          final String authToken = result.getString(AccountManager.KEY_AUTHTOKEN);
          final Intent authIntent = result.getParcelable(AccountManager.KEY_INTENT);
          if (accountName != null && authToken != null) {
            final SharedPreferences.Editor editor = settings.edit();
            editor.putString(PREF_TOKEN, authToken);
            editor.commit();
          } else if (authIntent != null) {
            activity.startActivity(authIntent);
          } else {
            Log.e(TAG, "AccountManager was unable to obtain an authToken.");
          }
        } catch (Exception e) {
          Log.e(TAG, "Auth Error", e);
        }
      }
    };

    AccountManager.get(activity).invalidateAuthToken("com.google", accessToken);
    AccountManager.get(activity).getAuthToken(account, SCOPE, true, cb, null);
  }
}