是否有更好的方法来解析这个JSON结构?

Question

我正在处理一个web服务，它定义了以下JSON结构作为GET到'positions'端点的返回:

{
"positions": {
"position": [
{
"cost_basis": 207.01,
"date_acquired": "2018-08-08T14:41:11.405Z",
"id": 130089,
"quantity": 1.00000000,
"symbol": "AAPL"
},
{
"cost_basis": 1870.70,
"date_acquired": "2018-08-08T14:42:00.774Z",
"id": 130090,
"quantity": 1.00000000,
"symbol": "AMZN"
},

这些都很好，除了当只有一个位置时，它们返回:

{
"positions":
{
"cost_basis": 1870.70,
"date_acquired": "2018-08-08T14:42:00.774Z",
"id": 130090,
"quantity": 1.00000000,
"symbol": "AMZN"
}
}

是否有一些行业技巧从JSON反序列化这个?我能想到的最好的是:

using (var httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, $"v1/accounts/{tradierHost.TradierAccount}/positions"))
using (HttpResponseMessage response = await this.tradierClient.SendAsync(httpRequestMessage))
{
// Make sure we executed with no errors.
response.EnsureSuccessStatusCode();
var jObject = JObject.Parse(await response.Content.ReadAsStringAsync());
IEnumerable<BrokerPosition> brokerPositions = null;
if (jObject["positions"] is JObject positionsObject)
{
// Update one position.
if (positionsObject["position"] is JObject positionObject)
{
var brokerPositionList = new List<BrokerPosition>();
brokerPositionList.Add(positionObject.ToObject<BrokerPosition>());
}
// Update many positions.
if (positionsObject["position"] is JArray positionArray)
{
brokerPositions = positionArray.ToObject<IEnumerable<BrokerPosition>>();
}
}
}

是否有更好的方法来解析这个供应商的API?我看不出有什么实用的方法来使用POCO。

Answer 1

我更喜欢使用构造函数

Data data = JsonConvert.DeserializeObject<Data>(json);

类

public class Data
{
public Positions Positions { get; set; } = new Positions();
[Newtonsoft.Json.JsonConstructor]
public Data(JToken positions)
{
var positionsObj = JObject.FromObject(positions);
if (positions["position"] != null)
Positions.Position = positionsObj["position"].ToObject<List<Position>>();
else
{
Positions.Position = new List<Position>();
Positions.Position.Add(positionsObj.ToObject<Position>());
}
}
}
public class Positions
{
public List<Position> Position { get; set; }
}
public class Position
{
public double cost_basis { get; set; }
public DateTime date_acquired { get; set; }
public int id { get; set; }
public double quantity { get; set; }
public string symbol { get; set; }
}

或者如果您不需要整个对象，则可以简单得多。你只需要一个类

var positionsObj = JObject.Parse(json)["positions"];

List<Position> positions = new List<Position>();
if (positionsObj["position"] != null)
positions = positionsObj["position"].ToObject<List<Position>>();
else
positions.Add(positionsObj.ToObject<Position>());

Answer 2

您可以定义您的类模型来使用它来解析模型中的JSON。用System.Text.Json或Newtonsoft.Json像例子:

var responseModel = JsonSerializer.Deserialize<YourReponseModel>(response.Content.ReadAsStringAsync());

可以通过对象属性responseModel.Positions

访问Position