Gson - convert from Json to a typed ArrayList<T> Gson - convert from Json to a typed ArrayList<T> json json

Gson - convert from Json to a typed ArrayList<T>

You may use TypeToken to load the json string into a custom object.

logs = gson.fromJson(br, new TypeToken<List<JsonLog>>(){}.getType());


Represents a generic type T.

Java doesn't yet provide a way to represent generic types, so this class does. Forces clients to create a subclass of this class which enables retrieval the type information even at runtime.

For example, to create a type literal for List<String>, you can create an empty anonymous inner class:

TypeToken<List<String>> list = new TypeToken<List<String>>() {};

This syntax cannot be used to create type literals that have wildcard parameters, such as Class<?> or List<? extends CharSequence>.


If you need to do it in Kotlin you can do it like this:

val myType = object : TypeToken<List<JsonLong>>() {}.typeval logs = gson.fromJson<List<JsonLong>>(br, myType)

Or you can see this answer for various alternatives.

Your JSON sample is:

{    "status": "ok",    "comment": "",    "result": {    "id": 276,    "firstName": "mohamed",    "lastName": "hussien",    "players": [            "player 1",            "player 2",            "player 3",            "player 4",            "player 5"    ]}

so if you want to save arraylist of modules in your SharedPrefrences so :

1- will convert your returned arraylist for json format using this method

public static String toJson(Object jsonObject) {    return new Gson().toJson(jsonObject);}

2- Save it in shared prefreneces

PreferencesUtils.getInstance(context).setString("players", toJson((.....ArrayList you want to convert.....)));

3- to retrieve it at any time get JsonString from Shared preferences like that

String playersString= PreferencesUtils.getInstance(this).getString("players");

4- convert it again to array list

public static Object fromJson(String jsonString, Type type) {    return new Gson().fromJson(jsonString, type);}ArrayList<String> playersList= (ArrayList<String>) fromJson(playersString,                    new TypeToken<ArrayList<String>>() {                    }.getType());

this solution also doable if you want to parse ArrayList of ObjectsHope it's help you by using Gson Library .


data class Player(val name : String, val surname: String)val json = [  {    "name": "name 1",    "surname": "surname 1"  },  {    "name": "name 2",    "surname": "surname 2"  },  {    "name": "name 3",    "surname": "surname 3"  }]val typeToken = object : TypeToken<List<Player>>() {}.typeval playerArray = Gson().fromJson<List<Player>>(json, typeToken)


val playerArray = Gson().fromJson(json, Array<Player>