I try to configure a one-to-many relation but when the hibernate session start-up and arrive to map my parent class the log give me a NullPointerException... why?

Error Report in Eclipse IDE:
Caused by: javax.faces.el.EvaluationException: java.lang.NullPointerException

at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:132)

at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:78)

... 32 more

Caused by: java.lang.NullPointerException

at jsflogin.CGUser.addUser(CGUser.java:78)

at jsflogin.AddUser.addUserAction(AddUser.java:51)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.sun.faces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:128)

... 33 more


Error Report in IE:
type Exception report

message

description The server encountered an internal error () that prevented it
from fulfilling this request.

exception

javax.servlet.ServletException: javax.faces.el.EvaluationException:
java.lang.NullPointerException
javax.faces.webapp.FacesServlet.service(FacesServlet.java:207)


root cause

javax.faces.FacesException: javax.faces.el.EvaluationException:
java.lang.NullPointerException

com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImp
l.java:83)
javax.faces.event.ActionEvent.processListener(ActionEvent.java:57)
javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:974)
javax.faces.component.UICommand.broadcast(UICommand.java:274)
javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:217)
javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:316)

com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhas
e.java:80)
com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:171)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:196)


note The full stack trace of the root cause is available in the Apache
Tomcat/5.0.27 logs.