RecordFilterStrategy don't allow to use child classes of the record value

[Kirill380]

I have a base class for Kafka events that inherited by specific DTO events classes related to a particular topic.
When I tried to filter Kafka events by RecordFilterStrategy parametrized with the base class I found out that I can't set up KafkaListenerContainerFactories parametrized with child DTO classes using this filter. I looked into the source code of the filter class and I figured out that the filter method doesn't use upper-bounded wildcard generic for ConsumerRecord so it means I can put only exactly the same type but not its successors.
It is better to use bounded generics to allow to put child classes.

[artembilan]

Please, raise a PullRequest and we will see what's going on.

Looks like I didn't have enough coffee after weekend, so not fully clear what's going on.

Thank you!

[Kirill380]

PR created

[artembilan]

Seems for me I see what is going on here.
Let's imagine we have a design like this:

public class Bar<T> {

    setFoo(Foo<T> foo) {
      ...
    }

}

The point is that Foo can handle target type, as well as its supper type.
So, what we really need here is something like this:

  setFoo(Foo<? super T> foo) 

So, this way into the new Bar<String>() we even can inject this setFoo(new Foo<CharSequence>()).

I believe this is the main point of this issue and this is exactly a design selected for the generics in Java core, e.g. Collection.removeIf(Predicate<? super E> filter).

Will issue some PR soon...