Implementing Generic Interface in Java

Question

I have a Java generics question I was hoping someone could answer. Consider the following code:

public interface Event{} public class AddressChanged implements Event{} public class AddressDiscarded implements Event{}  public interface Handles<T extends Event>{     public void handle(T event); } 

I want to implement this Handles interface like this:

public class AddressHandler implements Handles<AddressChanged>, Handles<AddressDiscarded>{     public void handle(AddressChanged e){}     public void handle(AddressDiscarded e){} } 

But java doesn't allow implementing Handles twice using the Generic. I was able to accomplish this with C#, but cannot figure a workaround in java without using Reflection or instanceof and casting.

Is there a way in java to implement the Handles interface using both generic interfaces? Or perhaps another way to write the Handles interface so the end result can be accomplished?

Answer 1

Going after @Amir Raminfar, you can use visitor pattern

interface Event{  void accept(Visitor v); } interface Visitor {  void visitAddressChanged(AddressChanged a);  void visitAddressDiscarded(AddressDiscarded a); }  class AddressChanged implements Event{  @Override  public void accept(Visitor v) {   v.visitAddressChanged(this);  }  }  class AddressDiscarded implements Event{  @Override  public void accept(Visitor v) {   v.visitAddressDiscarded(this);  }  }  class AddressHandler implements Visitor {     void handle(Event e){        e.accept(this);      }     public void visitAddressChanged(AddressChanged e){}     public void visitAddressDiscarded(AddressDiscarded e){} }