interface Visitor {
        public void visit(Employee employee);
        public void visit(Manager manager);
}
interface Visitable {
        public void accept(Visitor v);
}
class Employee implements Visitable {
        ...      
        public void accept(Visitor v) {
                v.visit(this);          
        }
}
class Manager extends Employee {
        ...
        public void accept(Visitor v) {
                v.visit(this);          
        }
}
public class Test {
        public static void main(String[] args) {
                ...
                Visitor v = new SomeVisitor();        // creeaza un obiect-vizitator concret
                for (Employee e : employees)
                        e.accept(v);                
        }
}