反序列化具有多个数据类型的JSON文件 [英] Deserialize JSON-File with multiple datatypes for a key

问题描述

我想分析Telegram-Chats，所以我以JSON格式导出了聊天，并想将其反序列化到我的分析软件中.

I wanted to analyze Telegram-Chats so I exported a chat in JSON format and wanted to deserialize it into my analyzing software.

    {
      "id": 397910,
      "type": "message",
      "date": "2018-02-21T10:27:59",
      "edited": "1970-01-01T01:00:00",
      "from": "Username",
      "from_id": 39033284,
      "text": "Some Text"
    }

所以我用了这个简单的代码来读取JSON

So I've used this simple code to read the JSON

    List<JSONObject> jsonObjects = JsonConvert.DeserializeObject<List<JSONObject>>(File.ReadAllText(openFileDialog.FileName));

    public class JSONObject
    {
       public int ID;
       public string type;
       public string date;
       public string edited;
       public string from;
       public int fromID;
       public string photo;
       public int width;
       public int height;
       public string text;
    }

这对于前525个数据集来说非常顺利，但是之后，由于一致性问题"，我在反序列化数据时遇到了麻烦.文本的数据类型有时会更改为数组.

This went very well for the first 525 datasets but afterwards, I had trouble deserializing the data because of "consistency issues". The Datatype of the text sometimes changes to an array.

    {
       "id": 397911,
       "type": "message",
       "date": "2018-02-21T10:31:47",
       "edited": "1970-01-01T01:00:00",
       "from": "Username",
       "from_id": 272964614,
       "text": [
          "Some Text ",
          {
             "type": "mention",
             "text": "@school"
          },
          " Some Text"
       ]
    }

我也找到了这个数据集

    {
       "id": 397904,
       "type": "message",
       "date": "2018-02-21T10:18:12",
       "edited": "1970-01-01T01:00:00",
       "from": "Username",
       "from_id": 39033284,
       "text": [
          {
             "type": "link",
             "text": "google.com"
          },
          "\n\nSome Text"
        ]
    }

当数据显示出这种不一致时，我不知道如何反序列化数据.

I don't know how I deserialize the data when it shows this kind of inconsistency.

推荐答案

由于属性很复杂，因此您需要编写自己的反序列化逻辑.

as your property is complex, you'll need to write your own de-serialization logic.

这是我的，但这只是一个例子:

Here's mine, but it's just an example :

• 首先，您的text属性似乎是
  • 单个值
  • 或值数组
  • First of all, your text property seems to be
    • A single value
    • Or an array of values

    在这种情况下，我将获得始终列表"结果，具有单个值的情况将只是具有一个条目的列表.

    In this case, I'll go for an "always list" result, the case with a single value will just be a list with one entry.

    public List<TextProperty> text;
    

    • 该值也可以是
      • 单个字符串值
      • 具有字符串值和元数据(文本类型)的对象
      • The value can also be
        • A single string value
        • An object with the string value and a meta datum (text type)

        同样，如果是字符串，我会去找一个没有类型的总是对象"

        Again, I'll go for an "always object" with no type if it's string only

        public class TextProperty
        {
            public string text { get; set; }
            public string type { get; set; }
        }
        

        然后，您必须创建自己的Converter来处理此问题，您只需从JsonConverter继承并实现逻辑

        Then you have to make your own Converter to handle this, you just have to inherit from JsonConverter and implement the logic

        public class TextPropertyConverter : JsonConverter
        {
            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
            {
                throw new NotImplementedException(); // not covered here
            }
        
            // A value can be either single string or object
            // Return a TextProperty in both cases
            private TextProperty ParseValue(JToken value) 
            {
                switch(value.Type)
                {
                    case JTokenType.String:
                        return new TextProperty { text = value.ToObject<string>() };
        
                    case JTokenType.Object:
                        return value.ToObject<TextProperty>();
        
                    default:
                        return null;
                }
            }
        
            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
            {
                // You'll start either with a single value (we'll convert to list of one value) or an array (list of several values then)
                switch(reader.TokenType)
                {
                    case JsonToken.String:
                    case JsonToken.StartObject:
                        return new List<TextProperty> { ParseValue(JToken.Load(reader)) };
        
                    case JsonToken.StartArray:
                        var a = JArray.Load(reader);
                        var l = new List<TextProperty>();
                        foreach(var v in a)
                            l.Add(ParseValue(v));
                        return l;
        
                    default:
                        return null;
                }
            }
        
            public override bool CanConvert(Type objectType) => false;
        }
        

        我认为所有情况都应该涵盖

        I think all cases should be covered

        要使用它，只需将JsonConverter属性添加到目标属性

        To use it, simply add the JsonConverter attribute to the target property

        public class JSONObject
        {
            public int id;
            public string type;
            public string date;
            public string edited;
            public string from;
            public int from_id;
            public string photo;
            public int width;
            public int height;
        
            [JsonConverter(typeof(TextPropertyConverter))]
            public List<TextProperty> text;
        }
        

        然后对其进行测试:

        static void Main(string[] args)
            {
                string json = @"
                [
                    {
                      ""id"": 397910,
                      ""type"": ""message"",
                      ""date"": ""2018-02-21T10:27:59"",
                      ""edited"": ""1970-01-01T01:00:00"",
                      ""from"": ""Username"",
                      ""from_id"": 39033284,
                      ""text"": ""Some Text""
                    },
        
                    {
                       ""id"": 397911,
                       ""type"": ""message"",
                       ""date"": ""2018-02-21T10:31:47"",
                       ""edited"": ""1970-01-01T01:00:00"",
                       ""from"": ""Username"",
                       ""from_id"": 272964614,
                       ""text"": [
                          ""Some Text "",
                          {
                             ""type"": ""mention"",
                             ""text"": ""@school""
                          },
                          "" Some Text""
                       ]
                    }
                ]";
        
                List<JSONObject> jsonObjects = JsonConvert.DeserializeObject<List<JSONObject>>(json);
        
                Console.Read();
            }
        

        结果如下:

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