如何在复杂的json对象中删除空字符串json值？

Question

I'm trying to upload JSON values to AWS Dynamo, and it looks like it's giving me a 400-type error when I upload values that have any properties with "" as values. The app I'm writing is a C# app.

What's the best way to remove any keys that have value of ""? I've seen how to remove null values, but I'm not sure this applies.

Say:

{myObj: { x: "", y: "test str" }, myStr: "hello world!"}

Becomes:

{myObj: { y: "test str" }, myStr: "hello world!"}

Answer 1

If you are using Newtonsoft's Json.NET library, you can play with JsonSerializerSettings and DefaultValue attribute:

public class Rootobject
{
    public Myobj myObj { get; set; }
    public string myStr { get; set; }
}

public class Myobj
{
    [DefaultValue("")]
    public string x { get; set; }
    [DefaultValue("")]
    public string y { get; set; }
}

var originalSerializedObject = "{myObj: { x: \"\", y: \"test str\" }, myStr: \"hello world!\"}";

var deserializedObject = JsonConvert.DeserializeObject<Rootobject>(originalSerializedObject);

var serializerSettings = new JsonSerializerSettings 
                             { 
                                NullValueHandling = NullValueHandling.Ignore, 
                                DefaultValueHandling = DefaultValueHandling.Ignore 
                             };

var newSerializedObject = JsonConvert.SerializeObject(deserializedObject, serializerSettings);

Console.WriteLine(newSerializedObject);
//{"myObj":{"y":"test str"},"myStr":"hello world!"}

Answer 2

If you do not want it to be applied to every single field, you could just add the following on the field that you would want to ignore when empty.

[DefaultValue("")]
[JsonProperty(NullValueHandling = NullValueHandling.Ignore, 
DefaultValueHandling = DefaultValueHandling.Ignore)]