Java generics method overriding

Question

I have interface:

public interface CartService extends RemoteService{
     T execute(Action action);
}

Answer 1

Your interface specifies that implementing classes must define that method for all T extends ActionResponse. You want to define them for specific actions, and responses - I think your interface needs to be

    public interface CartService>
     extends RemoteService {
      public T execute(A action)
    }

and then implementation would be

public class XX implements CartService {
 //...
}

As written, you may not need to explicitly parametrize with an extension of Action type - as long as you can deal with any kind of Action that is parametrized by GetCartResponse and don't rely on specifics of the GetCart action. In which case, your interface should look something like:

public interface CartService extends RemoteService {
 public T execute(Action action);
}

and implementation

public class XX implements CartService {
 public GetCartResponse execute(Action action) {
  //...
 }
}