Java Type Generic as Argument for GSON

Question

In GSON to get a list of objects you do

Gson gson = new Gson();
Type token = new TypeToken>(){}.getType();
return gson.fromJson(json         


        

Answer 1

If programming in kotlin, we can use reified type parameter in inline function

class GenericGson {

    companion object {
        inline fun <reified T : Any> Gson.fromJsonTokenType(jsonString: String): T {
            val type = object : TypeToken<T>() {}.type
            return this.fromJson(jsonString, type)
        }

        inline fun <reified T : Any> Gson.fromJsonType(jsonString: String): T = this.fromJson(jsonString, T::class.java)

        inline fun <reified T : Any> fromJsonTokenType(jsonString: String): T = Gson().fromJsonTokenType(jsonString)

        inline fun <reified T : Any> fromJsonType(jsonString: String): T = Gson().fromJsonType(jsonString)
    }
}

And use like below in your code

val arrayList = GenericGson.fromJsonTokenType<ArrayList<Person>>(json)