c# - 尝试使用 json.Net 反序列化 json 字符串时出错

Question

当我尝试反序列化以下简单的 json 字符串时遇到了一个奇怪的错误:

{ "items": [ "IZ01", "MTSQ", "VM16", "CR05" ]}

我从 json.net dll 得到的错误如下:

Invalid property identifier character: &. Path '', line 1, position 2.

完整的堆栈跟踪如下:

at Newtonsoft.Json.JsonTextReader.ParseProperty() at Newtonsoft.Json.JsonTextReader.ParseObject() at Newtonsoft.Json.JsonTextReader.ReadInternal() at Newtonsoft.Json.JsonTextReader.Read() at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CheckedRead(JsonReader reader) at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateObject(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue) at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.CreateValueInternal(JsonReader reader, Type objectType, JsonContract contract, JsonProperty member, JsonContainerContract containerContract, JsonProperty containerMember, Object existingValue) at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent) at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType) at Metastorm.Runtime.Models.SIMSCommonLib.UtilitiesLib.JSONDeserialize(String jsonText, Type valueType) at Metastorm.Runtime.Models.JobProject.ExternalExtendedHelper.GetMaintenanceCodesForVehicle(String LPEntityCode, String UMC, String VIN, String EquipmentList)

这是我用于反序列化 json 字符串的方法:

    public static object JSONDeserialize(string jsonText, Type valueType)
{
    Newtonsoft.Json.JsonSerializer json = new Newtonsoft.Json.JsonSerializer();

    json.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
    json.ObjectCreationHandling = Newtonsoft.Json.ObjectCreationHandling.Replace;
    json.MissingMemberHandling = Newtonsoft.Json.MissingMemberHandling.Ignore;
    json.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;

    StringReader sr = new StringReader(jsonText);
    Newtonsoft.Json.JsonTextReader reader = new JsonTextReader(sr);            
    object result = json.Deserialize(reader, valueType);
    reader.Close();

    return result;
}

我仅在我们应用程序的 UAT 环境中遇到此问题。奇怪的是，相同的代码和相同的数据在我们的开发和测试环境中都能正常工作。

知道为什么 json.net 报告字符“&”的问题吗？好像也没什么意思……

Answer 1

我设法自己解决了这个问题。

事实证明，我发送到方法“JSONDeserialize”的字符串是 HTML 编码的。

JSON 字符串，而不是以下内容:

{ "items": [ "IZ01", "MTSQ", "VM16", "CR05" ]}

实际上是这样的:

{ "items": [ "IZ01", "MTSQ", "VM16", "CR05" ]}

为了解决这个问题，我更新了“JSONDeserialize”方法，如下所示:

    public static object JSONDeserialize(string jsonText, Type valueType)
{
    // HTML-decode the string, in case it has been HTML encoded
    jsonText = System.Web.HttpUtility.HtmlDecode(jsonText);

    Newtonsoft.Json.JsonSerializer json = new Newtonsoft.Json.JsonSerializer();

    json.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
    json.ObjectCreationHandling = Newtonsoft.Json.ObjectCreationHandling.Replace;
    json.MissingMemberHandling = Newtonsoft.Json.MissingMemberHandling.Ignore;
    json.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;

    StringReader sr = new StringReader(jsonText);
    Newtonsoft.Json.JsonTextReader reader = new JsonTextReader(sr);            
    object result = json.Deserialize(reader, valueType);
    reader.Close();

    return result;
}