Authn (gradebook-service-api 22.5 API)

```
public interface Authn
```
Facade to abstract external authentication services. Since this is an application-wide singleton pointing to an otherwise opaque service, we do not assume that the authenticator has access to (for example) an up-to-date fully constructed FacesContext.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  String getUserUid()
  
  void setAuthnContext(Object whatToAuthn)

- Method Detail
  - getUserUid
```
String getUserUid()
```
    Returns:
    
    an ID uniquely identifying the currently authenticated user in a site, or null if the user has not been authenticated.
  - setAuthnContext
```
void setAuthnContext(Object whatToAuthn)
```
    Parameters:
    
    whatToAuthn - the javax.servlet.http.HttpServletRequest or javax.portlet.PortletRequest for which authentication should be checked. Since they don't share an interface, a generic object is passed.