Convert JSON from request into string c#

Question

I'm working with REST services from Oracle database, and I'm trying to cast the json response into my class model, but I can't get it, this is the type of the JSON

{
    "items": [
        {
            "id": 2,
            "role_id": 1,
            "local_id": 1,
            "nombre": "test",
            "apellido": "test",
            "email": "test",
            "phone_number": "123123",
            "rut": "1",
            "password": "1231212",
            "token": "C0C7C76D30BD3DCAEFC96F40275BDC0A"
        },
        {
            "id": 1,
            "role_id": 6,
            "local_id": 1,
            "nombre": "Cristobal",
            "apellido": "Gonzalez",
            "email": "cristobal@test.com",
            "phone_number": "22222",
            "rut": "2-1",
            "password": "actualizada",
            "token": "34173CB38F07F89DDBEBC2AC9128303F"
        }
    ],
    "hasMore": false,
    "limit": 25,
    "offset": 0,
    "count": 2,
    "links": [
        {
            "rel": "self",
            "href": "https://jl0ax7eh9vmstei-portafolio2020.adb.sa-saopaulo-1.oraclecloudapps.com/ords/admin/usuario/user"
        },
        {
            "rel": "describedby",
            "href": "https://jl0ax7eh9vmstei-portafolio2020.adb.sa-saopaulo-1.oraclecloudapps.com/ords/admin/metadata-catalog/usuario/item"
        },
        {
            "rel": "first",
            "href": "https://jl0ax7eh9vmstei-portafolio2020.adb.sa-saopaulo-1.oraclecloudapps.com/ords/admin/usuario/user"
        }
    ]
}

I just need to work with the items part, and my class is like

        public int id_usuario { get; set; }
        public int id_rol { get; set; }
        public int id_local { get; set; }
        public string pnombre { get; set; }
        public string papellido { get; set; }
        public string correo { get; set; }
        public string phone { get; set; }
        public string rut { get; set; }
        public string pass { get; set; }
        public string token { get; set; }

So my trouble is that when I try to Deserialize it, I can't parse into my class, I supposed that is for the "extra stuff" that I don't need... This is my method to convert into my class type

            string strresult_test = null;
            using (Stream stream = responseObjGet.GetResponseStream())
            {
                StreamReader sr = new StreamReader(stream);
                strresult_test = sr.ReadToEnd();
                strresult_test.ToString();
                Response.Write(sr);
                sr.Close();
            }

            var serial = new JavaScriptSerializer();

            ItemUsuario testv2 = JsonConvert.DeserializeObject<ItemUsuario>(strresult_test);
            Response.Write("g");
            List<ItemUsuario> salida = serial.Deserialize<List<ItemUsuario>>(strresult_test);

When I get the "testv2" variable, is null... What else can I do?

Thanks for the help!

Paste the JSON into QuickType.IO and it will generate a set of classes including de/serializers etc. There is a visual studio "paste Json as class" too but I think quick type's efforts go a bit further — Caius Jard, Jun 03 '20 at 18:23
ps; I note that the names in the Json seem to be completely different to those in the class, and no attributes anywhere to say what the mapping is; how did you map one to the other? — Caius Jard, Jun 03 '20 at 18:26

score 2 · Answer 1 · edited Jun 03 '20 at 18:33

Your model is wrong.

This is the correct way of doing it:

public partial class ItemUsuario
{
    [JsonProperty("items")]
    public Item[] Items { get; set; }

    [JsonProperty("hasMore")]
    public bool HasMore { get; set; }

    [JsonProperty("limit")]
    public long Limit { get; set; }

    [JsonProperty("offset")]
    public long Offset { get; set; }

    [JsonProperty("count")]
    public long Count { get; set; }

    [JsonProperty("links")]
    public Link[] Links { get; set; }
}

public partial class Item
{
    [JsonProperty("id")]
    public long Id { get; set; }

    [JsonProperty("role_id")]
    public long RoleId { get; set; }

    [JsonProperty("local_id")]
    public long LocalId { get; set; }

    [JsonProperty("nombre")]
    public string Nombre { get; set; }

    [JsonProperty("apellido")]
    public string Apellido { get; set; }

    [JsonProperty("email")]
    public string Email { get; set; }

    [JsonProperty("phone_number")]
    public string PhoneNumber { get; set; }

    [JsonProperty("rut")]
    public string Rut { get; set; }

    [JsonProperty("password")]
    public string Password { get; set; }

    [JsonProperty("token")]
    public string Token { get; set; }
}

public partial class Link
{
    [JsonProperty("rel")]
    public string Rel { get; set; }

    [JsonProperty("href")]
    public Uri Href { get; set; }
}

I generated this code using this tool. I have tested it and it works.

Guru Stron · Answer 2 · 2020-06-03T18:32:41.617

Your ItemUsuario array is actually value of property "items":

public class ItemContainer
{
        [JsonProperty("items")]
        public ItemUsuario[] Items { get; set; }
}  

public class ItemUsuario
{
    [JsonProperty("id")]
    public long Id { get; set; }

    [JsonProperty("role_id")]
    public long RoleId { get; set; }

    [JsonProperty("local_id")]
    public long LocalId { get; set; }
    .....
}

var result = JsonConvert.DeserializeObject<ItemContainer>(strresult_test);

score 0 · Answer 3 · answered Jun 03 '20 at 18:26

For the Deserialization to work make sure that the variable names in class matches with the names in the json. If you want to retain both as same, do consider decorating with the Attribute like

public class ItemUsuario
{
    //.. Line omitted for beveity
    [JsonProperty("role_id")]
    public string id_rol { get; set; }
    ...
}

Jawad · Answer 4 · 2020-06-03T19:07:54.280

If you want to deserialize that json into Just the class you are using, you will first need to get to the items object in the json and then deserialize it to your class. You can leverage JObject.Parse in combination with JsonConvert.DeserializeObject<YourClass>

This is a sample code that can be used to take that json into your class object.

var jsonObject = JObject.Parse(stresult_test);
List<ItemUsuario> testv2 = JsonConvert.DeserializeObject<List<ItemUsuario>>(jsonObject["items"].ToString());

jsonObject["items"] is an array / list so make sure you deserialize it to a List of your class.. not just the class itself.

As other posts suggests, and based on coding standards, use [JsonProperty("name")] in your class and make sure that the property Name matches the one in json.. otherwise you will get null for that property. in C#, the property names should start with a capital letter as well.

public class ItemUsuario {
  [JsonString("id")]
  public int Id {get;set}

  [JsonProperty("role_id")]
  public int RoleID {get;set;}
...

I did what you said, and when I try to loop into the list, I get a NullReferenceException, and the list has no object inside. Do I need a different type of cast? — Claudio Scabbia Sepúlveda, Jun 03 '20 at 19:54
if `stresult_test` contains the json that you posted, then the process written above would work. — Jawad, Jun 03 '20 at 20:12

Convert JSON from request into string c#

4 Answers4