Deserialize Nested Dictionary in from Json C#

Question

I have a class something like this

public class A{
    public Guid userId { get; set; }
    public Guid businessId { get; set; }
    public Dictionary<int, long> rights { get; set; }
}

And I want to covert this json to this class

    {
    "userId": "dc2af693-72e1-49a7-80aa-6416c6536bdf",
    "businessId": "0110eea4-7a47-4a7c-95ea-10547ab49652",
    "rights": "{\"19\":1,\"17\":15,\"18\":1,\"23\":1,\"1\":31,\"20\":3,\"3\":1,\"16\":0}",
   }

But when Im trying to convert it with NewtonSoft.Json

JsonConvert.DeserializeObject<A>(json);

I get the following error Cannot Cast System.string to System.Dictionary<int,long> What happens is that my rights get converted to a string something like this

"{"19":1, "17":15, "18":1, ..., "16":0}"

If I deserialize this string again it works as I desire is there better method to do this.

Actually the content of "rights" is a string, as all the quotes are escaped by backslashes (\") — keuleJ
– keuleJ, Commented Oct 5, 2021 at 12:58
Have you tried creating a sample object and serializing it first to see what it looks like serialized? I find this to be a good method of finding some of the more easy-to-miss errors when building complex strings. — CMGeek
– CMGeek, Commented Oct 5, 2021 at 13:00
The data in rights is effectively a Json representation of a dictionary, so this could be a two-step process: first deserialize rights as a string, them deserialize it again as a dictionary: Dictionary<int, long> RightValues => JsonConvert.DeserializeObject<Dictionary<int, long>>(rights); — stuartd
– stuartd, Commented Oct 5, 2021 at 13:05
@CMGeek this json is the payload of a jwt token where all of are added as claims to user of the token. — Muhammad Jamali
– Muhammad Jamali, Commented Oct 5, 2021 at 13:16
You'll need to decorate the rights property with a custom JsonConverter - in the custom JsonConverter you'll be able to deserialize the string and then convert into a dictionary. — Metro Smurf
– Metro Smurf, Commented Oct 5, 2021 at 13:19

Krishna Varma · Accepted Answer · 2021-10-05 13:47:08Z

3

Since the rights is in string format, you can add custom JsonConverter which converts the string to dictionary

public class A
{
    public Guid userId { get; set; }
    public Guid businessId { get; set; }
    [JsonConverter(typeof(RightsSerializer))]
    public Dictionary<int, long> rights { get; set; }
}

Here is the RightsSerializer

public class RightsSerializer : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return objectType == typeof(Dictionary<int, long>);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        if (reader.TokenType == JsonToken.Null) return null;

        var jt = JToken.Load(reader);
        return JsonConvert.DeserializeObject<Dictionary<int, long>>(jt.Value<String>());
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        serializer.Serialize(writer, value);
    }
}

And DeserializeObject

var json = File.ReadAllText("json1.json");
var result = JsonConvert.DeserializeObject<A>(json);

edited Oct 5, 2021 at 13:47

answered Oct 5, 2021 at 13:08

Krishna Varma

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2 Comments

Muhammad Jamali Over a year ago

I'm doing like this currently but the class is scoped which I can inject anywhere to get the value isn't there any short-hand where my class is contains the dictionary.

Krishna Varma Over a year ago

@MuhammadJamali, then you need custom runtime serializer. updated the post to reflect the same

Mojtaba Karimi · Accepted Answer · 2021-10-05 13:33:49Z

0

changing the class to something like this will help. althoutgh you need to make code better than this.

        public class A
    {
        public Guid userId { get; set; }
        public Guid businessId { get; set; }

        //[JsonConverter(typeof(Dictionary<int, long>))]
        public string rights { get; set; }

        public Dictionary<int, long> rightss => JsonConvert.DeserializeObject<Dictionary<int, long>>(rights);
    }

answered Oct 5, 2021 at 13:33

Mojtaba Karimi

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Comments

CMGeek · Accepted Answer · 2021-10-05 14:09:31Z

0

You can't do it without deserializing twice, but you could hide it with a private subclass.

public class A {
   public Guid userId {get;set;}
   public Guid businessId {get;set;}
   public Dictionary<int, long> rights {get;set;}

   private class B {
      public Guid userId {get;set;}
      public Guid businessId {get;set;}
      public string rights {get;set;}
   }

   private B b;

   public A (string json) {
      var o = new JsonSerializerOptions();
      o.AllowTrailingCommas = true;
      b = JsonSerializer.Deserialize<B>(json, o);
      userId = b.userId;
      businessId = b.businessId;
      rights = JsonSerializer.Deserialize<Dictionary<int, long>>(b.rights,o);
   }
}

Usage with test in fiddle:

Fiddle

edited Oct 5, 2021 at 14:09

answered Oct 5, 2021 at 13:38

CMGeek

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