Can you? The beauty of traits/type classes is that you can attach them to any type - in a world where 90% of the functionality of any piece of software is supplied by dependencies - external types which you cannot change - this is a vital feature.
It isn't pretty, but one can try to achieve a similar approach.
https://godbolt.org/z/TjPha3obs
Failing that, there are always Clojure, Kotlin and Scala on the JVM, which expose language features to achieve the same, which you naturally can mix and match with plain old Java.
I was responding to your original claim and I’m well aware of such facilities in both Kotlin and Scala - having used both extensively. I was genuinely curious if the latest Java was in the process of adding support for trait/typeclasses - so I don’t understand why you’d bother to reply with something that completely changes your original claim.