Basic Account Authenticator Service
suggest changeThe Android Account Authenticator system can be used to make the client authenticate with a remote server. Three pieces of information are required:
- A service, triggered by the
android.accounts.AccountAuthenticator
. ItsonBind
method should return a subclass ofAbstractAccountAuthenticator
. - An activity to prompt the user for credentials (Login activity)
- An xml resource file to describe the account
1. The service:
Place the following permissions in your AndroidManifest.xml:
<uses-permission android:name="android.permission.GET_ACCOUNTS" /> <uses-permission android:name="android.permission.MANAGE_ACCOUNTS" /> <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS" /> <uses-permission android:name="android.permission.USE_CREDENTIALS" />
Declare the service in the manifest file:
<service android:name="com.example.MyAuthenticationService"> <intent-filter> <action android:name="android.accounts.AccountAuthenticator" /> </intent-filter> <meta-data android:name="android.accounts.AccountAuthenticator" android:resource="@xml/authenticator" /> </service>
Note that the android.accounts.AccountAuthenticator
is included within the intent-filter
tag. The xml resource (named authenticator
here) is specified in the meta-data
tag.
The service class:
public class MyAuthenticationService extends Service { private static final Object lock = new Object(); private MyAuthenticator mAuthenticator; public MyAuthenticationService() { super(); } @Override public void onCreate() { super.onCreate(); synchronized (lock) { if (mAuthenticator == null) { mAuthenticator = new MyAuthenticator(this); } } } @Override public IBinder onBind(Intent intent) { return mAuthenticator.getIBinder(); } }
2. The xml resource:
<account-authenticator xmlns:android="http://schemas.android.com/apk/res/android" android:accountType="com.example.account" android:icon="@drawable/appicon" android:smallIcon="@drawable/appicon" android:label="@string/app_name" />
Do not directly assign a string to android:label
or assign missing drawables. It will crash without warning.
3. Extend the AbstractAccountAuthenticator class:
public class MyAuthenticator extends AbstractAccountAuthenticator { private Context mContext; public MyAuthenticator(Context context) { super(context); mContext = context; } @Override public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) throws NetworkErrorException { Intent intent = new Intent(mContext, LoginActivity.class); intent.putExtra(AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE, response); Bundle bundle = new Bundle(); bundle.putParcelable(AccountManager.KEY_INTENT, intent); return bundle; } @Override public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException { return null; } @Override public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) { return null; } @Override public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException { return null; } @Override public String getAuthTokenLabel(String authTokenType) { return null; } @Override public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException { return null; } @Override public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException { return null; } }
The addAccount()
method in AbstractAccountAuthenticator
class is important as this method is called when adding an account from the “Add Account” screen in under settings. AccountManager.KEY_ACCOUNT_AUTHENTICATOR_RESPONSE
is important, as it will include the AccountAuthenticatorResponse object that is needed to return the account keys upon successful user verification.