Kotlin convert json array to model list using GSON

Question

I am not able to convert a JSON Array into a GroupModel array. Below is the JSON I used:

[{
  \"description\":\"My expense to others\",
  \"items\"         


        

Answer 1

[{
  "description":"My expense to others",
  "items":["aaa","bbb"],
  "name":"My Expense"
 },
 {
  "description":"My expense to others","
  items":["aaa","bbb"],
  "name":"My Expense"
 }]

Kotlin Code

val gson = GsonBuilder().create()
val Model= gson.fromJson(body,Array<GroupModel>::class.java).toList()

Gradle

implementation 'com.google.code.gson:gson:2.8.5'

Answer 2

You need to use a TypeToken to capture the generic type of the array, and you need this to be the type that GSON sees as the target, instead of just GroupModel::class it is really a list of those. You can create a TypeToken and use it as follows:

Type groupListType = new TypeToken<ArrayList<GroupModel>>() {}.getType();
var model = gson.fromJson(inputString, groupListType);

Answer 3

I have found a solution that is actually working on Android with Kotlin for parsing JSON arrays of a given class. The solution of @Aravindraj didn't really work for me.

val fileData = "your_json_string"
val gson = GsonBuilder().create()
val packagesArray = gson.fromJson(fileData , Array<YourClass>::class.java).toList()

So basically, you only need to provide a class (YourClass in the example) and the JSON string. GSON will figure out the rest.

The Gradle dependency is:

implementation 'com.google.code.gson:gson:2.8.6'