（De-）序列化类似于Microsoft的已知类型-Java 学习之路

到目前为止，我将业务对象序列化和反序列化为格式为JSON的数据传输对象（DTO） . DTO标有DataContract属性 . 一个小例子：

[DataContract(Name = "Geometry", Namespace = "myContract.com/dto")]
[KnownType(typeof(Point))]
[KnownType(typeof(Line))]
public class Geometry
{
}

[DataContract(Name = "Point", Namespace = "myContract.com/dto")]
public class Point : Geometry
{
    [DataMember(Name = "x")]
    public double X { get; set; }

    [DataMember(Name = "y")]
    public double Y { get; set; }
}

[DataContract(Name = "Line", Namespace = "myContract.com/dto")]
public class Line: Geometry
{
    [DataMember(Name = "start")]
    public Point Start { get; set; }

    [DataMember(Name = "end")]
    public Point End { get; set; }
}

这被序列化为：

"geometry":{"__type":"Point:myContract.com/dto","x":23133.75569999963,"y":21582.385849999264}

由于性能问题，我改用了Newtonsoft Json.NET . 使用它时，JSON字符串如下所示：

"geometry":{"$type":"A.B.C.Point, A.B.C","x":23133.75569999963,"y":21582.385849999264}

是否有可能使用“__type”和 Contract 命名空间而不是“$ type”和类组装组合将Json.NET序列化为符合Microsoft的JSON字符串？我正在使用.NET 3.5 .

提前致谢！

1 回答

不幸的是，似乎无法调整属性名称，因为它在内部JsonTypeReflector.cs class中声明为：

public const string TypePropertyName = "$type";

注意：另一方面，可以自定义类型属性值，SerializationBinder类用于此目的，此示例演示如何指定自定义类型属性值 .

我建议以下允许编写自定义类型属性的解决方案 . 首先，我们需要引入具有type属性的基本实体类（或修改 Geometry 类），如下所示

[DataContract(Name = "Entity", Namespace = "myContract.com/dto")]
public abstract class Entity
{
    [DataMember(Name = "__type", Order = 0)]
    public string EntityTypeName
    {

        get
        {
            var typeName = GetType().Name;
            if (Attribute.IsDefined(GetType(), typeof(DataContractAttribute)))
            {
                var attribute = GetType().GetCustomAttributes(typeof(DataContractAttribute), true).FirstOrDefault() as DataContractAttribute;
                if (attribute != null) typeName = typeName + ":" + attribute.Namespace;
            }
            return typeName;
        }
    }
}

然后修改 Geometry 类：

[DataContract(Name = "Geometry", Namespace = "myContract.com/dto")]
[KnownType(typeof(Point))]
[KnownType(typeof(Line))]
public class Geometry : Entity
{
}

最后一步，将 JsonSerializerSettings.TypeNameHandling 设置为 TypeNameHandling.None ，以便反序列化器跳过 $type 属性的呈现 .

Example

var point = new Point { X = 23133.75569999963, Y = 21582.385849999264 };

  var jsonPoint = JsonConvert.SerializeObject(point, new JsonSerializerSettings
  {
       TypeNameHandling = TypeNameHandling.None,   //do not write type property(!)
  });
  Console.WriteLine(jsonPoint);

Result

{\"__type\":\"Point:myContract.com/dto\",\"x\":23133.75569999963,\"y\":21582.385849999264}

P.S.

您也可以使用DataMember.Order指定订单，如下所示：

[DataContract(Name = "Point", Namespace = "myContract.com/dto")]
public class Point : Geometry
{
    [DataMember(Name = "x",Order = 1)]
    public double X { get; set; }

    [DataMember(Name = "y", Order = 2)]
    public double Y { get; set; }
}

[DataContract(Name = "Line", Namespace = "myContract.com/dto")]
public class Line : Geometry
{
    [DataMember(Name = "start", Order = 1)]
    public Point Start { get; set; }

    [DataMember(Name = "end", Order = 2)]
    public Point End { get; set; }
}

回复于 2024-04-27T11:57:37+08:00

（De-）序列化类似于Microsoft的已知类型

1 回答

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