无法使用Json.NET 8.0.1反序列化具有字节数组属性的对象
无法使用Json.NET 8.0.1反序列化具有字节数组属性的对象
提问于 2016-01-07 11:37:16
在升级代码库以使用Json.NET 8.0.1之后，有些反序列化会出现问题。使用Json.NET 7.0.1，一切都很好。显然，导致问题的是byte[]类型属性的反序列化。如果我删除了byte[]属性，它就能正常工作。我可以使用这个简单的控制台应用程序再现这种行为：
internal class Program
{
private static void Main(string[] args)
{
Dictionary<string, Account> accounts;
var jsonSerializerSettings = new JsonSerializerSettings
{
TypeNameHandling = TypeNameHandling.Objects,
TypeNameAssemblyFormat = FormatterAssemblyStyle.Simple
};
using (var streamReader = new StreamReader("accounts.json"))
{
var json = streamReader.ReadToEnd();
accounts = JsonConvert.DeserializeObject<Dictionary<string, Account>>(json, jsonSerializerSettings);
}
foreach (var account in accounts)
{
Debug.WriteLine(account.Value.Name);
}
}
}
internal class Account
{
public string Id { get; set; }
public string Name { get; set; }
public byte[] EncryptedPassword { get; set; }
}accounts.json文件如下所示：
{
"$type": "System.Collections.Generic.Dictionary`2[[System.String, mscorlib],[ConsoleApplication1.Account, ConsoleApplication1]], mscorlib",
"lars.michael": {
"$type": "ConsoleApplication1.Account, ConsoleApplication1",
"EncryptedPassword": {
"$type": "System.Byte[], mscorlib",
"$value": "cGFzc3dvcmQ="
},
"Name": "Lars Michael",
"Id": "lars.michael"
},
"john.doe": {
"$type": "ConsoleApplication1.Account, ConsoleApplication1",
"EncryptedPassword": {
"$type": "System.Byte[], mscorlib",
"$value": "cGFzc3dvcmQ="
},
"Name": "John Doe",
"Id": "john.doe"
}
}这可能是Json.NET 8.0.1中的一个bug，还是我可以通过调整JsonSerializerSettings来解决这个问题？
如果有人试图复制该程序集，请确保将accounts.json文件中的程序集名称与控制台应用程序的程序集名称(在本例中为ConsoleApplication1)同步。
回答 1
Stack Overflow用户
回答已采纳
发布于 2016-01-07 14:10:33
更新
变更中的固定设置了70120，它将包含在Json.NET 8.0.2中。
原始答案
确认-这似乎是一个倒退。考虑以下简单的测试类：
internal class HasByteArray
{
public byte[] EncryptedPassword { get; set; }
}现在，如果我试着用TypeNameHandling.Objects往返全班
private static void TestSimple()
{
var test = new HasByteArray { EncryptedPassword = Convert.FromBase64String("cGFzc3dvcmQ=") };
try
{
TestRoundTrip(test);
}
catch (Exception ex)
{
Debug.WriteLine(ex);
}
}
private static void TestRoundTrip<T>(T item)
{
var jsonSerializerSettings = new JsonSerializerSettings
{
TypeNameHandling = TypeNameHandling.Objects,
TypeNameAssemblyFormat = FormatterAssemblyStyle.Simple
};
TestRoundTrip<T>(item, jsonSerializerSettings);
}
private static void TestRoundTrip<T>(T item, JsonSerializerSettings jsonSerializerSettings)
{
var json = JsonConvert.SerializeObject(item, Formatting.Indented, jsonSerializerSettings);
Debug.WriteLine(json);
var item2 = JsonConvert.DeserializeObject<T>(json, jsonSerializerSettings);
var json2 = JsonConvert.SerializeObject(item2, Formatting.Indented, jsonSerializerSettings);
Debug.WriteLine(json2);
if (!JToken.DeepEquals(JToken.Parse(json), JToken.Parse(json2)))
throw new InvalidOperationException("Round Trip Failed");
}我得到以下例外：
Newtonsoft.Json.JsonSerializationException: Additional text found in JSON string after finishing deserializing object.
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent) in C:\Development\Releases\Json\Working\Newtonsoft.Json\Working-Signed\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalReader.cs:line 196
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType) in C:\Development\Releases\Json\Working\Newtonsoft.Json\Working-Signed\Src\Newtonsoft.Json\JsonSerializer.cs:line 823
at Newtonsoft.Json.JsonSerializer.Deserialize(JsonReader reader, Type objectType) in C:\Development\Releases\Json\Working\Newtonsoft.Json\Working-Signed\Src\Newtonsoft.Json\JsonSerializer.cs:line 802
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings) in C:\Development\Releases\Json\Working\Newtonsoft.Json\Working-Signed\Src\Newtonsoft.Json\JsonConvert.cs:line 863
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings) in C:\Development\Releases\Json\Working\Newtonsoft.Json\Working-Signed\Src\Newtonsoft.Json\JsonConvert.cs:line 820
at Question34654184.TestClass.TestRoundTrip[T](T item, JsonSerializerSettings jsonSerializerSettings)
at Question34654184.TestClass.TestRoundTrip[T](T item)
at Question34654184.TestClass.TestSimple()Json7.0中没有出现异常。你应该报告问题。
同时，您可以使用以下转换器来解决问题：
public class ByteArrayConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return objectType == typeof(byte[]);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
var token = JToken.Load(reader);
if (token == null)
return null;
switch (token.Type)
{
case JTokenType.Null:
return null;
case JTokenType.String:
return Convert.FromBase64String((string)token);
case JTokenType.Object:
{
var value = (string)token["$value"];
return value == null ? null : Convert.FromBase64String(value);
}
default:
throw new JsonSerializationException("Unknown byte array format");
}
}
public override bool CanWrite { get { return false; } } // Use the default implementation for serialization, which is not broken.
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
throw new NotImplementedException();
}
}有设置
var jsonSerializerSettings = new JsonSerializerSettings
{
TypeNameHandling = TypeNameHandling.Objects,
TypeNameAssemblyFormat = FormatterAssemblyStyle.Simple,
Converters = new [] { new ByteArrayConverter() },
};页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/34654184
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