反序列化递归JSON对象

Question

我有一个像这样的递归JSON对象，表示一个查询表达式：

{
  "where": {
    "operator": "AND",
    "left": {
      "operator": "=",
      "$fieldRef": "requestor",
      "value": "@me"
    },
    "right": {
      "operator": "=",
      "$fieldRef": "state",
      "value": "Closed"
    }
  }
}

JSON层次结构中也可以出现更多的对象。这里有一个更复杂的例子：

{
  "where": {
    "operator": "OR",
    "left": {
      "operator": "=",
      "$fieldRef": "id",
      "value": "1234"
    },
    "right": {
      "operator": "OR",
      "left": {
        "operator": "=",
        "$fieldRef": "orgId",
        "value": "6757"
      },
      "right": {
        "operator": "AND",
        "left": {
          "operator": "STARTSWITH",
          "$fieldRef": "firstname",
          "value": "D"
        },
        "right": {
          "operator": "=",
          "$fieldRef": "state",
          "value": "Closed"
        }
      }
    }
  }
}

我希望能够将这个JSON反序列化为一些类，更新数据，然后再序列化回JSON。如何使用Json.NET完成此操作？

Answer 1

这样定义类：

class Query
{
    [JsonProperty("where")]
    public Clause Where { get; set; }
}
class Clause
{
    [JsonProperty("operator")]
    public string Operator { get; set; }
    [JsonProperty("left")]
    public Clause Left { get; set; }
    [JsonProperty("right")]
    public Clause Right { get; set; }
    [JsonProperty("$fieldref")]
    public string FieldRef { get; set; }
    [JsonProperty("value")]
    public string Value { get; set; }
}

然后你可以像这样反序列化：

Query q = JsonConvert.DeserializeObject<Query>(json);

您可以序列化回JSON，如下所示：

JsonSerializerSettings settings = new JsonSerializerSettings
{
    NullValueHandling = NullValueHandling.Ignore,
    Formatting = Formatting.Indented
};
json = JsonConvert.SerializeObject(q, settings);

以下是一个简单的演示：https://dotnetfiddle.net/qqAj2v