Hi i'm trying to create extension for Any object t...

# getting-started

[althaf]

Hi i'm trying to create extension for Any object to be convert to json, This is related generics, where i'm stuck at adapter<T>() , it is not able to match any of the exsisting signatures it has. Can any one help. I'm using Moshi here.

*inline fun* <*reified* T> Any.toCoCJson() {
*val* moshi: Moshi = Moshi.Builder().build()
*val* jsonAdapter: JsonAdapter<T> = moshi.adapter<T>()
*val* json: String = jsonAdapter.toJson(*this as* T)
}

[Sam]

Moshi is expecting either a Java Type or a Java Class. Given a reified Kotlin type, you can get its corresponding Java class with T::class.java, or you can get the Java Type with typeOf<T>().javaType. Of those two options, the second one is probably better, as it should be able to preserve more information about the type. So:

val jsonAdapter = moshi.adapter(typeOf<T>().javaType)

[Sam]

I'm a bit unsure about the intent of this function, though. Why do you want to accept Any and then cast it to T?

[althaf]

*return* jsonAdapter.toJson(*this*)

This was giving a compiler error

[althaf]

return jsonAdapter.toJson(this as T)

[althaf]

wouldn't this be correct ?

[Sam]

It would normally make more sense to change the function signature so that it accepts T instead of Any, unless there's a reason you can't use that approach.

inline fun <reified T> T.toCoCJson() { ... }

[althaf]

him, yes you are correct,

[althaf]

Thank you @Sam 🙂

[Sam]

Glad I could help!