I'm using a java library called Caffeine which is ...

# announcements

[Dalinar]

I'm using a java library called Caffeine which is actually fairly similar to Guava Caches in syntax. However, I've run into this problem (I'm extremely rusty on Kotlin since I haven't touched it in a year).. so.. how do I solve this? (make it nicer)

`
private val requests: Cache<String, Req> = Caffeine.newBuilder()
            .removalListener<String, Req> { clientOrderID: String?, req: Req?, removalCause: RemovalCause ->
                clientOrderID!!; req!!
                ...
                req.close()
            }
`

with Guava the code would compile without the `?

on the parameters

the reason I added these

!!where I did was because I refer to these variables several times in the code afterwards. However what I'm asking is if there is a nicer syntax where I can somehow get rid of the?` on the parameters

very strange, my other similar caches built in the same way have no problem accepting non-nullable parameters in removalListener - it's just this particular one that is the problem

[karelpeeters]

Well can those parameters actually be null? What do you want to do in that case?

[Dalinar]

no, I'm just replacing my old cache library with this new Caffeine one and ran into this problem. They shouldn't be null as can be seen in the <>

[karelpeeters]

Is that a Kotlin library?

[karelpeeters]

If so, the author of that library specifically chose those type to be nullable, and that probably means something.

[karelpeeters]

Otherwise, if it's a Java library, just remove the ? and you'll be using platform types.

[Dalinar]

java library.. the reason I added the `?s was because it wouldn't compile without them. They strange thing is that I have 3 different caches created in this way, but with different types inside <> and 2 of them require the?and the other one doesn't and I really can't see what the difference is. Caffeeine is very syntax-similar to Guava, and when I replaced it with Guava none of them require?`.. it's a puzzle

[karelpeeters]

Then there must be an @Nullable annotation.

[Dalinar]

ah I forgot about those, thanks

[Dalinar]

I will look into it

[karelpeeters]

And mostly look into why it's there simple smile