Deserialization issues JSON rest API

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I am reading 2 REST APIs using Httpclient in C#. The APIs return following employee data in JSON format:

**1st API** 

    {
        "status": "OK", 
        "content": {
            "empid1": 89900,
            "empid2": 45550,
            "empid3": 22350}
    }

**2nd API** 
   

     {
        "status": "OK", 
         "content": {
                  "empid1": "grade1",
                  "empid1": "grade2",
                  "empid1": "grade2"}
}

What I have tried:

Classes defined and code used is as follows:

C#

public class content
{
    public string empid { get; set; } // e.g. empid3
    public float salary { get; set; } // e.g. 89900
    public string grade { get; set; } // e.g. Grade1
}
public sealed class WrapperEmployees
{
    [JsonProperty("status")]
    public string Status { get; set; }

    [JsonProperty("content")]
    public List<content> empdata { get; set; } = new List<content>();
}

To deserialize, used this-

C#

WrapperEmployees nj = JsonConvert.DeserializeObject<WrapperEmployees>(response);

But, last line gives error on deserialization:

Cannot deserialize current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[CsharpSample.App_Code.Employee]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.    Path 'content.emp1', line 4, position 18.

Can you help me resolving this ? My ultimate aim is to fetch common data from both APIs against employee IDs.

Posted 5-Jul-21 2:08am

Member 15244870

Updated 31-Jul-22 16:52pm

v4

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2 solutions

Solution 2

Solution: 1
Make sure your both API returns as below
[{
        "status": "OK", 
        "content": {
            "empid1": 89900,
            "empid2": 45550,
            "empid3": 22350}
    }]{
Solution : 2
Update your wrapper class property as below
 [JsonProperty("content")]
 public content empdata { get; set; }

Try only either any one of these solutions definitely it works

Posted 31-Jul-22 16:52pm

Member 12274589

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Accepted Answer · 2021-07-05T02:21:00

Solution 1

Quote:

C#

[JsonProperty("data")]
public List<data> empdata { get; set; } = new List<data>();

According to the samples in your question, neither API returns a property called data.

They both have a property called content, but it is not a list; it's an object.

Assuming the property names aren't fixed, you could deserialize the first response into a Dictionary<string, int>:

C#

class FirstApiResponse
{
    [JsonProperty("status")]
    public string Status { get; set; }
    
    [JsonProperty("content")]
    public Dictionary<string, int> Content { get; set; }
}

The second API response cannot be deserialized into anything, since it uses the same property name for multiple properties in a single object.

Posted 5-Jul-21 2:21am

Richard Deeming

Comments

Member 15244870 5-Jul-21 8:28am

Thanks Richard for quick reply, I have corrected data to content, but issue exists. Kindly check now

Richard Deeming 5-Jul-21 8:31am

So you fixed one of the two issues I mentioned in my solution, and your code still doesn't work?

If only there was some clue as to what you should do next...

Member 15244870 5-Jul-21 8:37am

Richard, thanks Again. Your solution worked. But without serializing 2nd API, how will I extract common data of both API. So I have taken another class SecApiResponse as foll:
public Dictionary<string, string> empdata { get; set; }
public string Status { get; set; }

Then I'll execute a Linq query against both classes to get common results. Let me know if it is correct

Richard Deeming 5-Jul-21 8:46am

The sample of your second API response in your question shows an object with three properties, all named empid1.

If that's really what the response looks like, then it's not valid JSON. You won't be able to deserialize it to anything without a custom JSON converter.

If the object actually has different property names, as in the sample response from the first API, then you can deserialize it to a Dictionary<string, string>, and then use LINQ (or a foreach loop) to combine the responses.

Member 15244870 5-Jul-21 9:07am

Ok, I have taken one single class, dictionary argument is object, see as follows:
public sealed class APIResponse
{
[JsonProperty("status")]
public string Status { get; set; }

[JsonProperty("data")]
public Dictionary<string, object=""> empdata { get; set; }
}

Now I shall read response of 2 APIS into 2 diff objects of above class. Then I shall do a foreach loop inside both objects to get common data based on empid. Hope it sounds ok ?

Richard Deeming 5-Jul-21 9:14am

Yes, that should be fine, so long as the second API response doesn't reuse the same property names in a single object.

Deserialization issues JSON rest API

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Deserialization issues JSON rest API

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