Android OAuth2 Bearer令牌最佳做法

经过一番调查后我发现了自己的答案:

是的,调用AccountManager#invalidateAuthToken将删除上次保存的身份验证令牌(OAuth2案例中的访问令牌),并期望您在下次AccountAuthenticator#getAuthToken调用时检测到该令牌.例如,以下是该方法的代码:

@Override
public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
    // Extract the username and password from the Account Manager, and ask
    // for an appropriate AuthToken.
    final AccountManager am = AccountManager.get(mContext);

    String authToken = am.peekAuthToken(account, authTokenType);

    // EXTRA: I am also storing the OAuth2 refresh token in the AccountManager
    Map<String, String> refreshResult = null;
    String refreshToken = am.getUserData(account, KEY_REFRESH_TOKEN);
    if (TextUtils.isEmpty(authToken) && !TextUtils.isEmpty(refreshToken)) {
        // lets try to refresh the token
        // EXTRA: AuthenticationProvider is my class for accessing the authentication server, getting new access and refresh token based on the existing refresh token
        refreshResult = AuthenticationProvider.
            refreshAccessToken(am.getUserData(account, KEY_REFRESH_TOKEN));
    }

    // If we get a result from the refresh - we return it
    if (!refreshResult.isEmpty()) {
        authToken = refreshResult.get(AccountManager.KEY_AUTHTOKEN);
        // EXTRA: new refresh token used only in OAuth2
        refreshToken = refreshResult.get(KEY_REFRESH_TOKEN);

        final Bundle result = new Bundle();
        result.putString(AccountManager.KEY_ACCOUNT_NAME, account.name);
        result.putString(AccountManager.KEY_ACCOUNT_TYPE, account.type);

        // store the new tokens in the system
        am.setAuthToken(account, authTokenType, authToken);
        am.setUserData(account, KEY_REFRESH_TOKEN, refreshToken);

        result.putString(AccountManager.KEY_AUTHTOKEN, refreshResult.get(AccountManager.KEY_AUTHTOKEN));
        result.putString(KEY_REFRESH_TOKEN, refreshResult.get(KEY_REFRESH_TOKEN));
        return result;
    }

    // If we get here, then we couldn't access the user's password - so we
    // need to re-prompt them for their credentials. We do that by creating
    // an intent to display our AuthenticatorActivity.
    final Intent intent = new Intent(mContext, LoginActivity.class);
    intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response);
    final Bundle bundle = new Bundle();
    bundle.putParcelable(AccountManager.KEY_INTENT, intent);
    return bundle;
}

我还收到了问题中提到的博客文章的作者的确认.

SyncAdapters无法直接帮助,因为它们的真正目的是异步(对于开发人员)和透明地(对于用户)从网络获取数据.他们只是AbstractAccountAuthenticator在适当的时候使用并调用它的方法.