osgi - Why does the field from parent class has a null value when using in other class (Java/apache sling) -

in java code have following class:

@model(adaptables = slinghttpservletrequest.class) public class listmodel extends somelist{      @inject     protected resourceresolver resourceresolver;      //this method works fine:     public list<string> getalldata(){         system.out.println(resourceresolver.getuserid());     } } 

when call method getalldata() class, see user's id - fine.

now need write 2nd class extend 1 above. looks this:

public class mynextlistmodel extends listmodel{      //this method throws nullpointer because resourceresolver null - why?      @override      public list<listitemmodel> getallitems() {          system.out.println(resourceresolver.getuserid());      } } 

how come resourceresolver in 2nd class has null value?

i tried moving code:

@inject protected resourceresolver resourceresolver; 

from listmodel mynextlistmodel, though, it's still null in 2nd class

if class inheriting model missing @model annotation, sling not know do. add annotation inheriting class , code should work. btw make sure the other class in package registered sling models package in core pom.