Hi!
I am maintaining an application which is written in Kafka and uses the
kafka-streams library.
As said in the topic, after trying to upgrade from 0.10.1.1 to 0.10.2.1, I am
getting the following compilation error:
[error] found : service.streams.transformers.FilterMainCoverSupplier
[error] required: org.apache.kafka.streams.kstream.TransformerSupplier[_ >:
String, _ >: ?0(in value x$1), org.apache.kafka.streams.KeyValue[?,?]]
[error] Note: String <: Any (and
service.streams.transformers.FilterMainCoverSupplier <:
org.apache.kafka.streams.kstream.TransformerSupplier[String,dto.ContentDataDto,org.apache.kafka.streams.KeyValue[String,dto.ContentDataDto]]),
but Java-defined trait TransformerSupplier is invariant in type K.
[error] You may wish to investigate a wildcard type such as `_ <: Any`. (SLS
3.2.10)
[error] Note: dto.ContentDataDto <: Any (and
service.streams.transformers.FilterMainCoverSupplier <:
org.apache.kafka.streams.kstream.TransformerSupplier[String,dto.ContentDataDto,org.apache.kafka.streams.KeyValue[String,dto.ContentDataDto]]),
but Java-defined trait TransformerSupplier is invariant in type V.
[error] You may wish to investigate a wildcard type such as `_ <: Any`. (SLS
3.2.10)
[error] .transform(filterMainCover,
FilterMainCoverSupplier.StateStoreName)
The definition of the Transformer is as follows:
class FilterMainCover extends Transformer[String, ContentDataDto,
KeyValue[String, ContentDataDto]] {
}
The definition of the TransformerSupplier is as follows:
class FilterMainCoverSupplier extends TransformerSupplier[String,
ContentDataDto, KeyValue[String, ContentDataDto]] {
override def get(): Transformer[String, ContentDataDto, KeyValue[String,
ContentDataDto]] = new FilterMainCover()
}
I went through the confluent examples and could see that it is supposed to just
work. Anyone got an Idea what I am doing wrong?
Thanks
Björn
