JsonSerializer.Deserialize is returning empty object

Question

I have a webapi that returns some Json:

{"id":9,"businessName":"dummy","address":"pluto","products":[
{"id":762,"description":"Centralized needs-based website","price":1281.24,"stock":1600,"categories":[],"factory":null},
{"id":1027,"description":"Realigned 6th generation knowledge base","price":2398.16,"stock":19583,"categories":[],"factory":null},
{"id":1392,"description":"User-centric zero administration array","price":998.07,"stock":6124,"categories":[],"factory":null},
{"id":1800,"description":"Team-oriented reciprocal core","price":4422.95,"stock":17372,"categories":[],"factory":null},
{"id":2763,"description":"Sharable needs-based hierarchy","price":4122.98,"stock":17397,"categories":[],"factory":null},
{"id":6189,"description":"Re-engineered hybrid emulation","price":395.09,"stock":532,"categories":[],"factory":null}
]}

I then try to deserialize using:

using var response = await _httpClient.GetAsync($"{GetApiRouteFromEntity(entity)}/{entity.GetId()}");
        response.EnsureSuccessStatusCode();
        var responseContent = await response.Content.ReadAsStringAsync();
        T? item = JsonSerializer.Deserialize<T>(responseContent);

but this gives me an empty Factory with id 0 and all the other attributes to null

Factory.cs

public class Factory : EntityBase
    {
        [DisplayName("ID")]
        public int Id { get; set; }

        [DisplayName("Nome Business")]
        public string? BusinessName { get; set; }

        [DisplayName("Indirizzo")]
        public string? Address { get; set; }

        [DisplayName("Prodotti")] 
        public virtual ICollection<Product> Products { get; set; }
        
        public override string ToString()
        {
            return $"[{Id}] {BusinessName}";
        }
    }

Product.cs

public class Product : EntityBase
    {
        [DisplayName("ID")]
        public int Id { get; set; }

        [DisplayName("Descrizione")]
        public string? Description { get; set; }

        [DisplayName("Prezzo")]
        public float Price { get; set; }

        [DisplayName("Magazzino")]
        public int Stock { get; set; }

        [DisplayName("Categorie")]
        public virtual ICollection<Category> Categories { get; set; }

        [DisplayName("Fabbrica")]
        public virtual Factory Factory { get; set; }

        public override string ToString()
        {
            return $"[{Id}] {Description}";
        }
    }

EntityBase.cs

public abstract class EntityBase
    {
        public virtual object GetId()
        {
            return GetType().GetProperty("Id").GetValue(this);
        }
    }

i guess its because the factory prop in the products is null but idk how to work around that

Answer 1

From the docs:

By default, property names and dictionary keys are unchanged in the JSON output, including case.

You can specify the property naming policy:

T? item = JsonSerializer.Deserialize<T>(responseContent, new JsonSerializerOptions
{
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
});

to use camel case for all JSON property names, or mark all needed properties with JsonPropertyNameAttibute containing correct name:

public class Factory : EntityBase
{
    [DisplayName("ID")]
    [JsonPropertyName("id")] // and so on
    public int Id { get; set; }
    ....
}

Or set JsonSerializerOptions.PropertyNameCaseInsensitive to true.