For getting user attributes, WPF provides the com.bowstreet.webapp.util.UserInfo interface, via webAppAccess.getUserInfo();
From the UserInfo instance, you can get the user id, or get a list of known attributes and then for each, get the attribute value ...
See the WPF javadoc for more information on the UserInfo interface.
For getting group mappings and updating Portal user attributes, you would likely need to use the WebSphere Portal PUMA API.
See the WebSphere Portal documentation for more information on it's PUMA user and group management APIs.