Get JahiaDBUser on Portlets

Hi all,


i'm a noobie with jahia (i'm using 5.0.1) and I'm trying to devep a portlet.
Inside my portlet i need to get the username and password for user that is
accessing to portlet.
If i log "request.getUserPrincipal().getClass()" i get an JahiaDBuser:

"class: org.jahia.services.usermanager.JahiaDBUser"

But if i do:

JahiaDBUser juser = (JahiaDBUser) request.getUserPrincipal();

i get an exception:

"- JetspeedContainerServlet: Error rendering portlet
"MyPortletSystem::MyortletSystem": java.lang.ClassCastException:
org.jahia.services.usermanager.JahiaDBUser
java.lang.ClassCastException: org.jahia.services.usermanager.JahiaDBUser"

Can you help me?

Regards on advanced,

Ricardo Ferreira