import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import org.omg.CORBA.*;
import org.omg.PortableServer.*; 

public class printer extends printvisitorPOA
{
   public org.omg.CORBA.Object visitu (undergradHolder u)
    {  undergrad ug = u.value;
       System.out.println(ug.name()+" is an undergrad");
       // now, need to typecast "this" to a studentvisitor:
       // this is a printvisitorPOA, extends studentvisitorPOA,
       // which includes the _this() function

       if (ug.next() != null) ug.next().accept(this._this());
				  // this is it!
       return ug;
    }
 
   public org.omg.CORBA.Object visitg (gradHolder g)
    {
	System.out.println(g.value.name()+" is a graduate student");
	if (g.value.next() !=null) g.value.next().accept(this._this());
	return g.value;
    }

   
  public static void main(String[] args) 
  {
     try
     {
         // initialize local ORB
         ORB myorb = ORB.init(args,null);

         // initialize portable Object Adapter, glue to ORB
         POA rootpoa = (POA)myorb.resolve_initial_references("RootPOA");
         rootpoa.the_POAManager().activate();
         // Register objref with name service (similar to registry)
         org.omg.CORBA.Object nsobjref = 
             myorb.resolve_initial_references("NameService");
         //narrowing = CORBA type casting:
         NamingContext ncref = NamingContextHelper.narrow(nsobjref);

         // create instance of server object, call POA to convert to objref
         printer server = new printer();
         org.omg.CORBA.Object objref1 = rootpoa.servant_to_reference(server);

         NameComponent[] path1 = 
             { new NameComponent("printer","Object") };
         ncref.rebind(path1,objref1); // actual registration

         // now wait for client invocation
         System.out.println("waiting for client call...");
         myorb.run();
         
     } catch (Exception e) {e.printStackTrace();}
  } // main
}