在Amazon Cognito Userpool for Android中检索用户属性（别名，必需和自定义）

Question

The document below shows that we need to use GetDetailsHandler to retrieve user attributes for android.

http://docs.aws.amazon.com/cognito/latest/developerguide/tutorial-integrating-user-pools-android.html#tutorial-integrating-user-pools-user-details-android

I've tried that and in onSuccess(), I did

GetDetailsHandler getDetailsHandler = new GetDetailsHandler() {
        @Override
        public void onSuccess(CognitoUserDetails cognitoUserDetails) {
        Map userAtts = cognitoUserDetails.getAttributes().getAttributes();
        String userName =       userAtts.get("alias:preferred_username").toString();
        }

        @Override
        public void onFailure(Exception exception) {
       }
    };

username is still returned null. I implemented it in onCreate(). Am I doing it wrong? Any help is appreciated.

Answer 1

If you are trying to access the value in the standard user attribute "preferred_username", then the key is just "preferred_username".
To access the preferred username try this:

Map userAtts    = cognitoUserDetails.getAttributes().getAttributes();
String userName = userAtts.get("preferred_username").toString();

Answer 2

You have to initialize the map first after that you can use

Map userAtts=new HashMap();
userAtts =cognitoUserDetails.getAttributes().getAttributes();
String userName = userAtts.get("alias:preferred_username").toString();

it works