Visitor Pattern solution: few visitors have same interface but should work with different objects

Question

I have following class diagram (visitor pattern implementation):

Expected result:
1) WiredVisitor should visit only Router and WiredNetworkCard
2)

Answer 1

you can just define some interfaces and slap one on each of the sets of elements that you want it to visit...the advantages of doing it this way are:

• it is type safe
• no runtime checks (since they're not needed); no runtime exceptions

here is an implementation of what i'm talking about for your example:

• visitors:

  interface  Wired {
       R accept(Visitor v);
  
      interface Visitor {
          R visit(Router router);
  
          R visit(WiredNetworkCard wiredNetworkCard);
      }
  }
  
  interface Wireless {
       R accept(Visitor v);
  
      interface Visitor {
          R visit(Router router);
  
          R visit(WirelessNetworkCard wirelessNetworkCard);
      }
  }
  

• elements:

  class Router implements Wired, Wireless {
      @Override
      public  R accept(Wired.Visitor v) {
          return v.visit(this);
      }
  
      @Override
      public  R accept(Wireless.Visitor v) {
          return v.visit(this);
      }
  }
  
  class WiredNetworkCard implements Wired {
      @Override
      public  R accept(Wired.Visitor v) {
          return v.visit(this);
      }
  }
  
  class WirelessNetworkCard implements Wireless {
      @Override
      public  R accept(Wireless.Visitor v) {
          return v.visit(this);
      }
  }