I have a Kotlin data class that has an arg that can either be an Object or Array. Is there a way to de-serialize a string into this class and not care if not an Array but somehow get it into an array of one?
data class Game(var name:List<NameItem>)
data class NameItem(var title: String, var id: Int)
data can come back as both ways a single object or an array of objects( I have no control over the data as it is 3rd party data.
jsonString = "{"game":{"name":{"title":"GameName","id":22}}}"
jsonString = "{"game":{"name":[{"title":"GameName","id":22},{"title":"GameName2","id":23}]}}"
game: Game? = Gson().fromJson(jsonString Game::class.java)
my suggestions for solving your task
my solution if name is object, replace it with arrays
data class Game(var name:List<NameItem> )
data class NameItem(var title: String, var id: Int)
fun main(args: Array<String>) {
var json = "{\"game\":{\"name\":[{\"title\":\"game 1\",\"id\":1},{\"title\":\"game 2\",\"id\":2}]}}"
println(useJsonParser(json)) //Game(name=[NameItem(title=game 1, id=1), NameItem(title=game 2, id=2)])
json = "{\"game\":{\"name\":[{\"title\":\"game 1\",\"id\":1}]}}"
println(useJsonParser(json)) //Game(name=[NameItem(title=game 1, id=1), NameItem(title=game 2, id=2)])
json = "{\"game\":{\"name\":{\"title\":\"game 1\",\"id\":1}}}" // not array
println(useJsonParser(json)) //Game(name=[NameItem(title=game 1, id=1)])
}
version 1 -- created and registry adapter link @Cililing
fun useJsonParser(json: String): Game? {
val gson = GsonBuilder().registerTypeAdapter(Game::class.java, GameDeserializer()).create()
return gson.fromJson(json, Game::class.java)
}
class GameDeserializer : JsonDeserializer<Game?> {
override fun deserialize(json: JsonElement?, typeOfT: Type?, context: JsonDeserializationContext?): Game? {
val gameJson = json!!.asJsonObject.get("game")
if (gameJson.isJsonObject) {
val jsonName = gameJson.asJsonObject["name"]
val list = if (jsonName.isJsonObject) {
arrayOf(Gson().fromJson(jsonName, NameItem::class.java))
} else {
val fromJson = Gson().fromJson(jsonName, Array<NameItem>::class.java)
fromJson
}.toList()
return Game(list)
}
return null
}
}
version 2 -- manipulating the response
fun useJsonParser(json:String):Game?{
val jsonObject = JsonParser().parse(json).asJsonObject.get("game")
if(jsonObject.asJsonObject["name"].isJsonObject){
val jsonName = jsonObject.asJsonObject["name"].asJsonObject
val array = JsonArray()
array.add(jsonName)
jsonObject.asJsonObject.add("name", array) // rewrite origin JSON
}
return Gson().fromJson(jsonObject, Game::class.java)
}
vesrion 3 -- add adapter TypeToken>()
fun useJsonParser(json: String): Game? {
val type = object : TypeToken<MutableList<NameItem>>() {}.type
val gson = GsonBuilder().registerTypeAdapter(type, NameItemDeserializer()).create()
return gson.fromJson(JsonParser().parse(json).asJsonObject.get("game"), Game::class.java)
}
class NameItemDeserializer : JsonDeserializer<List<NameItem>?> {
override fun deserialize(json: JsonElement, type: Type, context: JsonDeserializationContext?): List<NameItem>? {
with(json){
return if(isJsonObject){
arrayListOf(Gson().fromJson(this,NameItem::class.java))
}else{
Gson().fromJson(this,Array<NameItem>::class.java).toList()
}
}
}
}