Ø 前言
说起 C# 对 JSON 的操作(序列化与反序列化),大家都会想到 JavaScriptSerializer、DataContractJsonSerializer 与 Newtonsoft.Json 等。三者都是用于操作 JSON 的框架利器,它们又有什么区别呢?本文包括:
1. 常用 JSON 操作框架(JavaScriptSerializer、DataContractJsonSerializer、Newtonsoft.Json)的区别与比较
2. 简单序列化与反序列化
3. 匿名对象
4. DataTable
5. 私有成员
6. 指定成员名称
7. 指定序列化成员
8. 枚举类型成员
1. 常用 JSON 操作框架(JavaScriptSerializer、DataContractJsonSerializer、Newtonsoft.Json)的区别与比较
1) 区别如下:
1. JavaScriptSerializer,位于 System.Web.Extensions.dll程序集,它是.NET 自带的程序集,适用于 Web 项目中,因为每当新建一个 Web 项目后,VS 都会自动帮我引用该程序集,
2. DataContractJsonSerializer,位于 System.Runtime.Serialization.dll程序集,也是属于 .NET 自带的程序集。适用于 WCF 项目中,因为每当新建一个 WCF 项目后,VS 都会自动帮我引用该程序集。另外,由名称可见它是一种“数据契约 JSON 序列化”。
3. Newtonsoft.Json,一个第三方的开源类库,主要处理数据的 JSON 序列化操作,在性能或功能方面与前两者相比都有优势,官网:https://www.newtonsoft.com/json,适用于对 JSON 数据操作平凡的各种项目中。
2) 性能比较
1. 下图是 Newtonsoft.Json 官网给出的执行耗时比较
2. Newtonsoft.Json 官网当然说自己的牛逼,所以,本人在本机进行了代码验证,代码如下:
string jssStr, dcjsStr, jcStr;
Person[] jssArr, dcjsArr, jcArr;
int count = 100000;
Person[] persons = newPerson[count];
for (int i = 0; i < count; i++)
{
persons[i] = newPerson()
{
Name = string.Format("李三毛_{0}", i),
Age = 29,
Sex = true,
Address = "湖北省利川市",
Spouse = newPerson()
{
Name = string.Format("大美妞_{0}", i),
Age = 25,
Sex = false,
Address = "湖北省利川市",
Spouse = null
}
};
}
System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch();
//3.1 JavaScriptSerializer
JavaScriptSerializer jss = newJavaScriptSerializer();
jss.MaxJsonLength = 92097152; //默认为:2097152
stopwatch.Restart();
jssStr = jss.Serialize(persons);
stopwatch.Stop();
Console.WriteLine("JavaScriptSerializer Serialize Time【{0:F1}s,{1}ms】,String Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, jssStr.Length);
stopwatch.Restart();
jssArr = jss.Deserialize<Person[]>(jssStr);
stopwatch.Stop();
Console.WriteLine("JavaScriptSerializer Deserialize Time【{0:F1}s,{1}ms】,Array Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, jssArr.Length);
//3.2 DataContractJsonSerializer
DataContractJsonSerializer dcjs = newDataContractJsonSerializer(typeof(Person[]));
stopwatch.Restart();
using (MemoryStream stream = newMemoryStream())
{
dcjs.WriteObject(stream, persons);
dcjsStr = Encoding.UTF8.GetString(stream.ToArray());
}
stopwatch.Stop();
Console.WriteLine("DataContractJsonSerializer Serialize Time【{0:F1}s,{1}ms】,String Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, dcjsStr.Length);
stopwatch.Restart();
using (MemoryStream stream = newMemoryStream(Encoding.UTF8.GetBytes(dcjsStr)))
{
dcjsArr = dcjs.ReadObject(stream) asPerson[];
}
stopwatch.Stop();
Console.WriteLine("DataContractJsonSerializer Deserialize Time【{0:F1}s,{1}ms】,Array Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, dcjsArr.Length);
//3.3 Newtonsoft.Json
stopwatch.Restart();
jcStr = JsonConvert.SerializeObject(persons);
stopwatch.Stop();
Console.WriteLine("Newtonsoft.Json Serialize Time【{0:F1}s,{1}ms】,String Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, jcStr.Length);
stopwatch.Restart();
jcArr = JsonConvert.DeserializeObject<Person[]>(jcStr);
stopwatch.Stop();
Console.WriteLine("Newtonsoft.Json Deserialize Time【{0:F1}s,{1}ms】,Array Length:{2}",
TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds, stopwatch.ElapsedMilliseconds, jcArr.Length);
Ø 运行结果(三者分别运行三次后的最短耗时)
1. Serialize(序列化)
1) DataContractJsonSerializer Serialize Time【0.7s,696ms】,String Length:14377781
2) Newtonsoft.Json Serialize Time【1.7s,1741ms】,String Length:14377781
3) JavaScriptSerializer Serialize Time【6.2s,6189ms】,String Length:14377781
2. Deserialize(反序列化)
1) DataContractJsonSerializer Deserialize Time【2.0s,2037ms】,Array Length:100000
2) Newtonsoft.Json Deserialize Time【2.4s,2407ms】,Array Length:100000
3) JavaScriptSerializer Deserialize Time【3.7s,3733ms】,Array Length:100000
Ø 可见,耗时最短的并不是 Newtonsoft.Json,而是 .NET 自带的 DataContractJsonSerializer,最差的是 JavaScriptSerializer,序列化用了6秒,而 DataContractJsonSerializer 则之需要1秒时间不到。所以这一局,DataContractJsonSerializer 胜出,而 Newtonsoft.Json 则稍微靠后,由于它的功能方面比较强大,所以还是继续研究它。
Ø 首先,我们定义一个测试的类,并创建类的实例和一个匿名对象(后面的示例基本都使用该类)
1. 定义测试类(Goods 为一个部分类)
/// <summary>
///商品
///</summary>
publicpartial classGoods
{
///<summary>
///商品Id
///</summary>
publicint GoodsId { get; set; }
///<summary>
///商品名称
///</summary>
publicstring GoodsName { get; set; }
///<summary>
///价格
///</summary>
publicdecimal Price { get; set; }
///<summary>
///是否限购
///</summary>
publicbool IsQuota { get; set; }
///<summary>
///商品属性数组
///</summary>
publicAttribute[] Attributes { get; set; }
///<summary>
///商品属性
///</summary>
publicclassAttribute
{
publicstring Name { get; set; }
publicstring Value { get; set; }
}
}
2. 创建类的实例
Goods[] goods = newGoods[]
{
newGoods()
{
GoodsId = 1,
GoodsName = "联想ThinkPad无线鼠标",
Price = 125.00m,
IsQuota = true,
Attributes = newGoods.Attribute[]
{
newGoods.Attribute() { Name = "品牌", Value = "Lenovo/联想" },
newGoods.Attribute() { Name = "颜色", Value = "黑色" }
}
}
};
var anonymousGoods = new[]
{
new
{
GoodsId = 2,
GoodsName = "联想ThinkPad无线键盘",
Price = 286.00m,
IsQuota = false,
Attributes = new []
{
new { Name = "品牌", Value = "Lenovo/联想" },
new { Name = "颜色", Value = "白色" }
}
}
};
2. 简单序列化与反序列化
1) 序列化
序列化通常使用 JsonConvert类的 SerializeObject方法,该方法有6 个重载方法,例如:
string jsonStr1_1 = JsonConvert.SerializeObject(goods);
结果:
[{"GoodsId":1,"GoodsName":"联想ThinkPad无线鼠标","Price":125.00,"IsQuota":true,"Attributes":[{"Name":"品牌","Value":"Lenovo/联想"},{"Name":"颜色","Value":"黑色"}]}]
2) 反序列化
序列化通常使用 JsonConvert类的 DeserializeObject方法,该方法有8 个重载方法,例如:
Goods[] jsonObj1_1 = JsonConvert.DeserializeObject<Goods[]>(jsonStr1_1);
结果:
3. 匿名对象
1) 序列化
string jsonStr1_2 = JsonConvert.SerializeObject(anonymousGoods);
结果:
[{"GoodsId":2,"GoodsName":"联想ThinkPad无线键盘","Price":286.00,"IsQuota":false,"Attributes":[{"Name":"品牌","Value":"Lenovo/联想"},{"Name":"颜色","Value":"白色"}]}]
2) 反序列化
var jsonObj1_2 = JsonConvert.DeserializeAnonymousType(jsonStr1_2, anonymousGoods);
结果:
4. DataTable
首先,创建一个 DataTable 对象并插入数据
DataTable dataTable = newDataTable();
dataTable.Columns.AddRange(newDataColumn[]
{
newDataColumn() { ColumnName = "GoodsId", DataType = typeof(int) },
newDataColumn() { ColumnName = "GoodsName", DataType = typeof(string) },
newDataColumn() { ColumnName = "Price", DataType = typeof(decimal) }
});
for (int i = 0; i < 2; i++)
{
DataRow dataRow = dataTable.NewRow();
dataRow["GoodsId"] = i + 1;
dataRow["GoodsName"] = string.Format("测试商品{0}", i + 1);
dataRow["Price"] = i + 101;
dataTable.Rows.Add(dataRow);
}
1) 序列化
string jsonStr3_1 = JsonConvert.SerializeObject(dataTable);
结果:[{"GoodsId":1,"GoodsName":"测试商品1","Price":101.0},{"GoodsId":2,"GoodsName":"测试商品2","Price":102.0}]
2) 反序列化
DataTable jsonObj3_1 = JsonConvert.DeserializeObject<DataTable>(jsonStr3_1);
结果:
5. 私有成员(以 Price、IsQuota为例)
Newtonsoft.Json 默认是不处理 private(私有)成员的,如非要处理也是可以的,在私有成员上标记 JsonPropertyAttribute特性即可,例如(修改 Goods):
privatedecimal _price = 126;
///<summary>
///价格
///</summary>
privatedecimal Price { get { return _price; } set { _price = value; } }
privatebool _isQuota = true;
///<summary>
///是否限购
///</summary>
[JsonProperty]
privatebool IsQuota { get { return _isQuota; } set { _isQuota = value; } }
1) 序列化
string jsonStr4_1 = JsonConvert.SerializeObject(goods);
结果:
[{"GoodsId":1,"GoodsName":"联想ThinkPad无线鼠标","IsQuota":true,"Attributes":[{"Name":"品牌","Value":"Lenovo/联想"},{"Name":"颜色","Value":"黑色"}]}]
2) 反序列化
Goods[] jsonObj4_1 = JsonConvert.DeserializeObject<Goods[]>(jsonStr4_1);
结果:
6. 指定成员名称
使用 JsonPropertyAttribute特性的PropertyName属性指定 JSON 成员名称,例如(修改 Goods):
[JsonProperty("att_name")]
publicstring Name { get; set; }
[JsonProperty("att_val")]
publicstring Value { get; set; }
1) 序列化
string jsonStr5_1 = JsonConvert.SerializeObject(goods);
结果:
[{"GoodsId":1,"GoodsName":"联想ThinkPad无线鼠标","IsQuota":true,"Attributes":[{"att_name":"品牌","att_val":"Lenovo/联想"},{"att_name":"颜色","att_val":"黑色"}]}]
2) 反序列化
Goods[] jsonObj5_1 = JsonConvert.DeserializeObject<Goods[]>(jsonStr5_1);
结果:
7. 指定序列化成员
Newtonsoft.Json 提供三种序列化模式,使用 Newtonsoft.Json.MemberSerialization枚举表示。例如(修改 Goods):
[JsonObject(Newtonsoft.Json.MemberSerialization.OptIn)]
publicclassGoods {...}
///<summary>
///商品名称
///</summary>
[JsonProperty]
publicstring GoodsName { get; set; }
OptOut | 默认值,序列化所有共有成员,可以使用 JsonIgnore特性,标记不需要序列化的成员。 |
OptIn | 只序列化标记 JsonProperty特性的成员。 |
Fields | 只序列化字段成员。注意:默认情况下字段也支持序列化和反序列化。 |
1) 序列化
string jsonStr6_1 = JsonConvert.SerializeObject(goods);
结果:[{"GoodsName":"联想ThinkPad无线鼠标","IsQuota":true}]
2) 反序列化
Goods[] jsonObj6_1 = JsonConvert.DeserializeObject<Goods[]>(jsonStr6_1);
结果:
8. 枚举类型成员
枚举类型成员默认情况下,是序列化枚举类型的值。如果希望序列化成员名称,需要在成员上标记 JsonConverter特性,并指定Newtonsoft.Json.Converters.StringEnumConverter类型,例如(修改 Goods):
///<summary>
///商品状态
///</summary>
publicenumStatus
{
///<summary>
///无
///</summary>
None = 0,
///<summary>
///上架
///</summary>
Online = 1,
///<summary>
///下架
///</summary>
Offline = 2
}
///<summary>
///商品扩展
///</summary>
publicpartialclassGoods
{
///<summary>
///商品状态
///</summary>
[JsonProperty]
[JsonConverter(typeof(Newtonsoft.Json.Converters.StringEnumConverter))]
publicStatus Status { get; set; }
}
1) 序列化
string jsonStr7_1 = JsonConvert.SerializeObject(goods);
结果:[{"GoodsName":"联想ThinkPad无线鼠标","IsQuota":true,"Status":"Online"}]
2) 反序列化
Goods[] jsonObj7_1 = JsonConvert.DeserializeObject<Goods[]>(jsonStr7_1);
结果: