Java generics method overriding

Question

I have interface:

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

Answer 1

The problem is the definition of the interface vs what the erausre should look like for your impl. In your example you have:

 T execute(Action action);
public  GetCartResponse execute(GetCart action);

but according to the interface definition the implementation method should read:

public GetCartResponse execute(Action action);

So I think you either need to change the signature of your interface or add another type parameter such as:

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

or possibly something along the lines of:

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