Pass DataType of the Class - json

Question

I have the following data class, which stores two values, JSON and dataType:
data class DataTypeItem(
var json : String = "",
var dataType : Class<*> ?= null
)
I have the list defined in the following way:
val dataTypeList = mutableMapOf<String, DataTypeItem>()
dataTypeList.put( "item_1", DataTypeItem( json1, MyDataType::class.java ) )
dataTypeList.put( "item_2", DataTypeItem( json1, List<MyDataType>::class.java ) )
Please note that in one case I'm using the MyDataType as the DataType and in the other List < MyDataType >.
Now I would like to loop through each of the dataTypeList items and parse JSON for the given data type into it's model:
fun init()
{
dataTypeList.forEach {
dataTypeItem ->
val model = Gson().fromJson( dataTypeItem.value.json, dataTypeItem.value.dataType::class.java )
}
}
I'm using the following model:
data class dataTypeItem(
#SerializedName("sqlId")
val sqlId: String,
#SerializedName("name")
val name: String
)
But I keep getting an Runtime exception:
Attempted to deserialize a java.lang.Class. Forgot to register a type adapter?
In addition, in case it's a list, I need to call toList() on Gson().fromJSON(..):
fun init()
{
dataTypeList.forEach {
dataTypeItem ->
val model;
if( dataTypeItem.value.dataType::class.java is Array )
model = Gson().fromJson( dataTypeItem.value.json, dataTypeItem.value.dataType::class.java ).toList()
else
model = Gson().fromJson( dataTypeItem.value.json, dataTypeItem.value.dataType::class.java )
}
}
How can I pass the dataType dynamically and distinguish if it's a List/Array or straight up class? In addition, whenever I try to call toList(), I get an error that it's undefined.
If I specify the class directly, then it's working fine
var model = Gson().fromJson( json, DataTypeItem::class.java )
or
var model = Gson().fromJson( json, Array<DataTypeItem>::class.java )
but I need to be able to specify it dynamically as an argument

Answer 1

This code works fine:
val dataTypeMap = mapOf(
"item_1" to MyDataTypeItem("""{"sqlId" : "1", "name" : "a"}""", MyDataType::class.java),
"item_2" to MyDataTypeItem("""[{"sqlId" : "1", "name" : "a"}, {"sqlId" : "2", "name" : "b"}]""", Array<MyDataType>::class.java)
)
val result = dataTypeMap.map{ Gson().fromJson(it.value.json, it.value.dataType) }
I renamed DataTypeItem to MyDataTypeItem and dataTypeItem to MyDataType.
Why you need to call toList()? If it is really necessary you can do the following instead:
val result = dataTypeMap.map {
if (it.value.dataType?.isArray == true) Gson().fromJson<Array<*>>(it.value.json, it.value.dataType).toList()
else Gson().fromJson(it.value.json, it.value.dataType)
}