Android Android Authenticator Basic Account Authenticator Service
Example
The 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. ItsonBindmethod 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.
