I've found that function that correctly work for the JSON parse:
var objs = JObject.Load(new JsonTextReader(new StreamReader(JsonPath)))
.SelectTokens("*")
.Select(t => JsonConvert.DeserializeObject<Cars>(t.ToString()));
but it doesn't release the file after use it (so I can not use it for other function) ... I've tried to use the function Close, but seems not working over the object!
P.s. i've checked the previous open-one question, releated to this topic, but nobody talk about how to access to the object fileds, and seems the qeustion are different if we count that i have more than 1 object ... guess someone can explain better how it works ...
From the JSON.NET Site Read JSON from a File :
// read JSON directly from a file
using (StreamReader file = File.OpenText(#"c:\videogames.json"))
using (JsonTextReader reader = new JsonTextReader(file))
{
JObject o2 = (JObject)JToken.ReadFrom(reader);
}
The question's code does something unnecessary though - it tries to serialize the already deserialized JObject back into JSON, then deserialize it again as a Car. Why not deserialize the original file just once?
The docs describe this too in Deserialize JSON from a file:
// deserialize JSON directly from a file
using (StreamReader file = File.OpenText(#"c:\movie.json"))
{
JsonSerializer serializer = new JsonSerializer();
Movie movie2 = (Movie)serializer.Deserialize(file, typeof(Movie));
}
JSON documents can contain only a single object. If the file contents look like this :
{
"Movies":[{
"Title":"abc"
}, {
"Title":"abc"
}]
}
The root object should contain a Movies property that holds a Movie[] array :
class RootObjedt
{
public Movie[] Movies{get;set;}
}
...
using (StreamReader file = File.OpenText(#"c:\movie.json"))
{
JsonSerializer serializer = new JsonSerializer();
var root = (Movie)serializer.Deserialize(file, typeof(RootObject));
var movies=root.Movies;
}
I recommend you to read your json data async because this method have overload that takes stream as an input, so you can read data in two strings of code like this:
ProjFolder\Program.cs
using System.IO;
using System.Text.Json;
using System.Threading.Tasks;
using StackOverflow.Models;
namespace StackOverflow
{
class Program
{
static async Task Main(string[] args)
{
using var openStream = File.OpenRead(#"D:\Code\test.json");
var result = await JsonSerializer.DeserializeAsync<Root>(openStream);
// You need to get car2 Costo
var costo = result.Car2.Costo;
}
}
}
ProjFolder\Models\Root.cs
using System.Text.Json.Serialization;
namespace StackOverflow.Models
{
public class Root
{
[JsonPropertyName("car1")]
public Car Car1 { get; set; }
[JsonPropertyName("car2")]
public Car Car2 { get; set; }
}
}
ProjFolder\Models\Car.cs
namespace StackOverflow.Models
{
public class Car
{
public string CasaAutomobilistica { get; set; }
public string Modello { get; set; }
public string AnnoImmatricolazione { get; set; }
public string Targa { get; set; }
public int KM { get; set; }
public bool Finanziamento { get; set; }
public int Porte { get; set; }
public int Costo { get; set; }
}
}
{
"car1":
{
"CasaAutomobilistica": "Fiat",
"Modello": "500",
"AnnoImmatricolazione": "2017",
"Targa": "AZ978AG",
"KM": 120000,
"Finanziamento" : true,
"Porte" : 5,
"Costo" : 6000
},
"car2":
{
"CasaAutomobilistica": "BMW",
"Modello": "Serie 1",
"AnnoImmatricolazione": "2019",
"Targa": "BC978AG",
"KM": 150000,
"Finanziamento" : false,
"Porte" : 3,
"Costo" : 12000
}
}
First, read the file with surrounded by using block and do JSON operation
Better place it in a separate method as below
private string readFile()
{
string buffer = null;
using (System.IO.FileStream stm = new
System.IO.FileStream("c:\\YourFile.txt",System.IO.FileMode.Open,
System.IO.FileAccess.Read, System.IO.FileShare.None))
{
using (System.IO.StreamReader rdr = new System.IO.StreamReader (stm))
{
buffer=rdr.ReadToEnd();
}
}
return buffer
}
private Object Deserialize(string content)
{
//do conversion here
}
Related
I have been reading How To Parse XML In .NET Core There they show an example on parsing XML using XMLSerializer.
[XmlRoot("MyDocument", Namespace = "http://www.dotnetcoretutorials.com/namespace")]
public class MyDocument
{
public string MyProperty { get; set; }
public MyAttributeProperty MyAttributeProperty { get; set; }
[XmlArray]
[XmlArrayItem(ElementName = "MyListItem")]
public List MyList { get; set; }
}
public class MyAttributeProperty
{
[XmlAttribute("value")]
public int Value { get; set; }
}
and to read it:
using (var fileStream = File.Open("test.xml", FileMode.Open))
{
XmlSerializer serializer = new XmlSerializer(typeof(MyDocument));
var myDocument = (MyDocument)serializer.Deserialize(fileStream);
Console.WriteLine($"My Property : {myDocument.MyProperty}");
Console.WriteLine($"My Attribute : {myDocument.MyAttributeProperty.Value}");
foreach(var item in myDocument.MyList)
{
Console.WriteLine(item);
}
}
In the code above itreads the local xml file:
using (var fileStream = File.Open("test.xml", FileMode.Open)).
I want to read an XML file from URL, and make use of XmlSerializer, how would I accomplish this?
Since you already have your XML parsing logic in place, all you need is to swap out the file reading for an HTTP request.
using (var client = new HttpClient())
{
var content = await client.GetStreamAsync("http://...");
XmlSerializer serializer = new XmlSerializer(typeof(MyDocument));
var myDocument = (MyDocument)serializer.Deserialize(new MemoryStream(content));
Console.WriteLine($"My Property : {myDocument.MyProperty}");
Console.WriteLine($"My Attribute : {myDocument.MyAttributeProperty.Value}");
foreach(var item in myDocument.MyList)
{
Console.WriteLine(item);
}
}
I am trying to deserialize JSON file and want to assign to object ScanResult. var text showing all the values but scanresult showing null some null values. https://gyazo.com/ff2ce386f845394c458a88d43a1f30d8
please suggest if I am missing something.
//MY jSon File SCAN Test 1-1543045410222.json 's code
{
"at": 1543045410222,
"i": 1000,
"s": {
"Sensor1": ["OFF"],
"Sensor2": ["OFF"],
"DataReady1": ["OFF"],
"DataReady2": ["OFF"],
"CV1": [5.0],
"CV2": [6.0]
}
}
//ViewModel Code is as below:
public void ResendScanResult()
{
var ScanActivities = scanActivityManager.GetAll();
foreach (var item in ScanActivities)
{
var scanName = item.ScanName;
var dir = _dataFilePath + scanName + "\\";
var jsonFileName = string.Format("{0}{1}-{2}.json", dir, scanName, item.ScanDateEpoch);
string fileName = Path.GetFileName(jsonFileName);
// ScanResult scanResult = new ScanResult();
var text = File.ReadAllText(jsonFileName);
//var scanResults = JsonConvert.DeserializeObject<ScanResult>(text);
Common.Model.ScanResult scanResult = JsonConvert.DeserializeObject<Common.Model.ScanResult>(text);
var Mvm = MonitorViewModel.Instance;
// TargetProvider target = Mvm.GetTargetProvider(scanResult);
// Mvm.PublishToServer(target, scanResult);
}
}
and my scanRescult class code is as below :
namespace ABX.Common.Model
{
public class ScanResult
{
public ScanResult()
{
At = DateTimeOffset.Now.ToUnixTimeMilliseconds();
Interval = 1;
}
public string Name { get; set; }
public long At { get; set; }
public long Interval { get; set; }
public JObject Values { get; set; }
public string FileName { get; set; }
public JObject ToJson()
{
JObject json = new JObject
{
{ "at", At },
{ "i", Interval },
{ "s", Values }
};
return json;
}
Either rename your class properties to match your JSON, rename your JSON to match your class properties, or implement a custom JsonConverter, where you can implement arbitrary mapping.
I have to read a JSON stream (which I have no control over), which is in the form:
{"files":
{
"/some_file_path.ext": {"size":"1000", "data":"xxx", "data2":"yyy"},
"/other_file_path.ext": {"size":"2000", "data":"xxx", "data2":"yyy"},
"/another_file_path.ext": {"size":"3000", "data":"xxx", "data2":"yyy"},
}
}
So, I have an object named files, which has a number of properties, which have 1) different names every time, 2) different number of them every time, and 3) names with characters which can't be used in C# properties.
How do I deserialize this?
I'm putting this into a Portable Library, so I can't use the JavaScriptSerializer, in System.Web.Script.Serialization, and I'm not sure about JSON.NET. I was hoping to use the standard DataContractJsonSerializer.
UPDATE: I've changed the sample data to be closer to the actual data, and corrected the JSON syntax in the area the wasn't important. (Still simplified quite a bit, but the other parts are fairly standard)
You can model your "files" object as a Dictionary keyed by the JSON property name:
public class RootObject
{
public Dictionary<string, PathData> files { get; set; }
}
public class PathData
{
public int size { get; set; }
public string data { get; set; }
public string data2 { get; set; }
}
Then, only if you are using .Net 4.5 or later, you can deserialize using DataContractJsonSerializer, but you must first set DataContractJsonSerializerSettings.UseSimpleDictionaryFormat = true:
var settings = new DataContractJsonSerializerSettings { UseSimpleDictionaryFormat = true };
var root = DataContractJsonSerializerHelper.GetObject<RootObject>(jsonString, settings);
With the helper method:
public static class DataContractJsonSerializerHelper
{
public static T GetObject<T>(string json, DataContractJsonSerializer serializer = null)
{
using (var stream = GenerateStreamFromString(json))
{
var obj = (serializer ?? new DataContractJsonSerializer(typeof(T))).ReadObject(stream);
return (T)obj;
}
}
public static T GetObject<T>(string json, DataContractJsonSerializerSettings settings)
{
return GetObject<T>(json, new DataContractJsonSerializer(typeof(T), settings));
}
private static MemoryStream GenerateStreamFromString(string value)
{
return new MemoryStream(Encoding.Unicode.GetBytes(value ?? ""));
}
}
Alternatively, you can install Json.NET and do:
var root = JsonConvert.DeserializeObject<RootObject>(jsonString);
Json.NET automatically serializes dictionaries to JSON objects without needing to change settings.
We need to first convert this Invalid JSON to a Valid JSON. So a Valid JSON should look like this
{
"files":
{
"FilePath" : "C:\\some\\file\\path",
"FileData" : {
"size": 1000,
"data": "xxx",
"data2": "yyy"
},
"FilePath" :"C:\\other\\file\\path",
"FileData" : {
"size": 2000,
"data": "xxx",
"data2": "yyy"
},
"FilePath" :"C:\\another\\file\\path",
"FileData" : {
"size": 3000,
"data": "xxx",
"data2": "yyy"
}
}
}
To make it a valid JSON we might use some string functions to make it looks like above. Such as
MyJSON = MyJSON.Replace("\\", "\\\\");
MyJSON = MyJSON.Replace("files", "\"files\"");
MyJSON = MyJSON.Replace("data:", "\"data:\"");
MyJSON = MyJSON.Replace("data2", "\"data2\"");
MyJSON = MyJSON.Replace(": {size", ",\"FileData\" : {\"size\"");
MyJSON = MyJSON.Replace("C:", "\"FilePath\" :\"C:");
Than we can create a class like below to read the
public class FileData
{
public int size { get; set; }
public string data { get; set; }
public string data2 { get; set; }
}
public class Files
{
public string FilePath { get; set; }
public FileData FileData { get; set; }
}
public class RootObject
{
public Files files { get; set; }
}
Assuming you have a valid JSON you could use JavaScriptSerializer to return a list of objects
string json = "{}"
var serializer = new JavaScriptSerializer();
var deserializedValues = (Dictionary<string, object>)serializer.Deserialize(json, typeof(object));
Alternatively you could specify Dictionary<string, List<string>> as the type argument
strign json = "{}";
JavaScriptSerializer serializer = new JavaScriptSerializer();
var deserializedValues = serializer.Deserialize<Dictionary<string, List<string>>>(json);
foreach (KeyValuePair<string, List<string>> kvp in deserializedValues)
{
Console.WriteLine(kvp.Key + ": " + string.Join(",", kvp.Value));
}
What's the difference between JsonConvert.DeserializeObject and JObject.Parse? As far as I can tell, both take a string and are in the Json.NET library. What kind of situation would make one more convenient than the other, or is it mainly just preference?
For reference, here's an example of me using both to do exactly the same thing - parse a Json string and return a list of one of the Json attributes.
public ActionResult ReadJson()
{
string countiesJson = "{'Everything':[{'county_name':null,'description':null,'feat_class':'Civil','feature_id':'36865',"
+"'fips_class':'H1','fips_county_cd':'1','full_county_name':null,'link_title':null,'url':'http://www.alachuacounty.us/','name':'Alachua County'"+ ",'primary_latitude':'29.7','primary_longitude':'-82.33','state_abbreviation':'FL','state_name':'Florida'},"+
"{'county_name':null,'description':null,"+ "'feat_class':'Civil','feature_id':'36866','fips_class':'H1','fips_county_cd':'3','full_county_name':null,'link_title':null,'url':'http://www.bakercountyfl.org/','name':'Baker County','primary_latitude':'30.33','primary_longitude':'-82.29','state_abbreviation':'FL','state_name':'Florida'}]}";
//Can use either JSONParseObject or JSONParseDynamic here
List<string> counties = JSONParseObject(countiesJson);
JSONParseDynamic(countiesJson);
return View(counties);
}
public List<string> JSONParseObject(string jsonText)
{
JObject jResults = JObject.Parse(jsonText);
List<string> counties = new List<string>();
foreach (var county in jResults["Everything"])
{
counties.Add((string)county["name"]);
}
return counties;
}
public List<string> JSONParseDynamic(string jsonText)
{
dynamic jResults = JsonConvert.DeserializeObject(jsonText);
List<string> counties = new List<string>();
foreach(var county in jResults.Everything)
{
counties.Add((string)county.name);
}
return counties;
}
The LINQ-to-JSON API (JObject, JToken, etc.) exists to allow working with JSON without needing to know its structure ahead of time. You can deserialize any arbitrary JSON using JToken.Parse, then examine and manipulate its contents using other JToken methods. LINQ-to-JSON also works well if you just need one or two values from the JSON (such as the name of a county).
JsonConvert.DeserializeObject, on the other hand, is mainly intended to be used when you DO know the structure of the JSON ahead of time and you want to deserialize into strongly typed classes. For example, here's how you would get the full set of county data from your JSON into a list of County objects.
class Program
{
static void Main(string[] args)
{
string countiesJson = "{'Everything':[{'county_name':null,'description':null,'feat_class':'Civil','feature_id':'36865',"
+"'fips_class':'H1','fips_county_cd':'1','full_county_name':null,'link_title':null,'url':'http://www.alachuacounty.us/','name':'Alachua County'"+ ",'primary_latitude':'29.7','primary_longitude':'-82.33','state_abbreviation':'FL','state_name':'Florida'},"+
"{'county_name':null,'description':null,"+ "'feat_class':'Civil','feature_id':'36866','fips_class':'H1','fips_county_cd':'3','full_county_name':null,'link_title':null,'url':'http://www.bakercountyfl.org/','name':'Baker County','primary_latitude':'30.33','primary_longitude':'-82.29','state_abbreviation':'FL','state_name':'Florida'}]}";
foreach (County c in JsonParseCounties(countiesJson))
{
Console.WriteLine(string.Format("{0}, {1} ({2},{3})", c.name,
c.state_abbreviation, c.primary_latitude, c.primary_longitude));
}
}
public static List<County> JsonParseCounties(string jsonText)
{
return JsonConvert.DeserializeObject<RootObject>(jsonText).Counties;
}
}
public class RootObject
{
[JsonProperty("Everything")]
public List<County> Counties { get; set; }
}
public class County
{
public string county_name { get; set; }
public string description { get; set; }
public string feat_class { get; set; }
public string feature_id { get; set; }
public string fips_class { get; set; }
public string fips_county_cd { get; set; }
public string full_county_name { get; set; }
public string link_title { get; set; }
public string url { get; set; }
public string name { get; set; }
public string primary_latitude { get; set; }
public string primary_longitude { get; set; }
public string state_abbreviation { get; set; }
public string state_name { get; set; }
}
Notice that Json.Net uses the type argument given to the JsonConvert.DeserializeObject method to determine what type of object to create.
Of course, if you don't specify a type when you call DeserializeObject, or you use object or dynamic, then Json.Net has no choice but to deserialize into a JObject. (You can see for yourself that your dynamic variable actually holds a JObject by checking jResults.GetType().FullName.) So in that case, there's not much difference between JsonConvert.DeserializeObject and JToken.Parse; either will give you the same result.
JsonConvert.DeserializeObject has one advantage over JObject.Parse:
It is possible to use custom JsonSerializerSettings.
This can be very useful e.g. if you want to control how dates are deserialized.
By default dates are deserialized into DateTime objects.
This means that you may end up with a date with another time zone than the one in the json string.
You can change this behaviour by creating a JsonSerializerSetting and setting
DateParseHandling to DateParseHandling.DateTimeOffset.
An example:
var json = #"{ ""Time"": ""2015-10-28T14:05:22.0091621+00:00""}";
Console.WriteLine(json);
// Result: { "Time": "2015-10-28T14:05:22.0091621+00:00" }
var jObject1 = JObject.Parse(json);
Console.WriteLine(jObject1.ToString());
// Result: { "Time": "2015-10-28T15:05:22.0091621+01:00" }
var jObject2 = Newtonsoft.Json.JsonConvert.DeserializeObject(json,
new Newtonsoft.Json.JsonSerializerSettings
{
DateParseHandling = Newtonsoft.Json.DateParseHandling.DateTimeOffset
});
Console.WriteLine(jObject2.ToString());
// Result: { "Time": "2015-10-28T14:05:22.0091621+00:00" }
For me the key difference I was interested in was Speed.
I made a simple test to find out if it was faster to use JToken.Parse(string) or DeserializeObject<JToken>(string) to create a large amount of JToken and these were the results after 2,000,000 iterations using a sample of real world data
Method
Operating System Ticks
Milliseconds
JsonConvert
86123945
8612ms
JToken
67671724
6767ms
There was some variation between runs but the difference was always large.
Here is the test so you can modify it or run it yourself:
private static string s = #"{'stream':'btcusdt #bookTicker','data':{'u':20430107433,'s':'BTCUSDT','b':'21223.72000000','B':'3.29440000','a':'21223.73000000','A':'2.05450000'}}";
private static Stopwatch sw = new Stopwatch();
private static void Main(string[] args)
{
JToken convert = default;
sw.Restart();
for (int i = 0; i < 2000000; i++)
{
convert = JsonConvert.DeserializeObject<JToken>(s);
}
Console.WriteLine("JsonConvert: " + sw.ElapsedTicks + " [" + sw.ElapsedMilliseconds + "ms]");
convert.ToString();
convert = default;
sw.Restart();
for (int i = 0; i < 2000000; i++)
{
convert = JToken.Parse(s);
}
Console.WriteLine("JToken : " + sw.ElapsedTicks + " [" + sw.ElapsedMilliseconds + "ms]");
convert.ToString();
Console.ReadLine();
}
I knew an advantage that JsonConvert.DeserializeObject can deserialize an Array/List json text directly, but JObject cannot.
Try below sample code:
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
namespace NetCoreJsonNETDemo
{
internal class Person
{
[JsonProperty]
internal string Name
{
get;
set;
}
[JsonProperty]
internal int? Age
{
get;
set;
}
}
internal class PersonContainer
{
public List<Person> Persons
{
get;
set;
}
}
class Program
{
static T RecoverPersonsWithJsonConvert<T>(string json)
{
return JsonConvert.DeserializeObject<T>(json);
}
static T RecoverPersonsWithJObejct<T>(string json) where T : class
{
try
{
return JObject.Parse(json).ToObject<T>();
}
catch (Exception ex)
{
Console.WriteLine("JObject threw an Exception: " + ex.Message);
return null;
}
}
static void Main(string[] args)
{
List<Person> persons = new List<Person>();
persons.Add(new Person()
{
Name = "Jack",
Age = 18
});
persons.Add(new Person()
{
Name = "Sam",
Age = null
});
persons.Add(new Person()
{
Name = "Bob",
Age = 36
});
string json = JsonConvert.SerializeObject(persons, new JsonSerializerSettings()
{
Formatting = Formatting.Indented
});
List<Person> newPersons = RecoverPersonsWithJsonConvert<List<Person>>(json);
newPersons = RecoverPersonsWithJObejct<List<Person>>(json);//JObject will throw an error, since the json text is an array.
PersonContainer personContainer = new PersonContainer()
{
Persons = persons
};
json = JsonConvert.SerializeObject(personContainer, new JsonSerializerSettings()
{
Formatting = Formatting.Indented
});
newPersons = RecoverPersonsWithJObejct<PersonContainer>(json).Persons;
newPersons = null;
newPersons = RecoverPersonsWithJsonConvert<PersonContainer>(json).Persons;
Console.WriteLine("Press any key to end...");
Console.ReadKey();
}
}
}
Apart from the answers provided here around usage, which are correct as per me :
Jobject.Parse -> when the Json is not strongly Typed or you do not know the structure of Json ahead of time
JsonConvert.DeserializeObject<T> -> When you know which class or type to cast the Json in. T can be a complex class or a simple type
My answer is based on the performance in case where the structure is not known, as given in the OP code, if we benchmark the usage of both methods for performance, it is observed that Jobject.Parse() fares well in terms of allocated memory, please ignore the name of methods, I am first calling the method with 'JsonConvert.DeserializeObject' and then second method is with Jobject.Parse
How can I deserialize:
{
"data": [
{"ForecastID":8587961,"StatusForecast":"Done"},
{"ForecastID":8588095,"StatusForecast":"Done"},
{"ForecastID":8588136,"StatusForecast":"Done"},
{"ForecastID":8588142,"StatusForecast":"Pending"}
]
}
to
class RawData
{
public string data { get; set; }
}
So, I just want to have
[
{"ForecastID":8587961,"StatusForecast":"Done"},
{"ForecastID":8588095,"StatusForecast":"Done"},
{"ForecastID":8588136,"StatusForecast":"Done"},
{"ForecastID":8588142,"StatusForecast":"Pending"}
]
as value of property data of RawData's class instance.
Using Json.Net
var obj = (JObject)JsonConvert.DeserializeObject(json);
var newJson = obj["data"].ToString();
or using built-in JavaScriptSerializer
var dict = new JavaScriptSerializer().Deserialize<Dictionary<string, object>>(json);
var newjson = new JavaScriptSerializer().Serialize(dict["data"]);
It would have made far much more sense to deserialize this JSON structure to:
public class Forecast
{
public IEnumerable<ForecastData> Data { get; set; }
}
public class ForecastData
{
public int ForecastID { get; set; }
public string StatusForecast { get; set; }
}
which is pretty trivial with the JavaScriptSerializer class that's built into the framework:
string json = "your JSON data here";
IEnumerable<ForecastData> data = new JavaScriptSerializer()
.Deserialize<Forecast>(json)
.Data;
or if you don't want to define models you could do that:
dynamic result = new JavaScriptSerializer().DeserializeObject(json);
foreach (var item in result["data"])
{
Console.WriteLine("{0}: {1}", item["ForecastID"], item["StatusForecast"]);
}