JsonDocument Get JSON String - c#

I need an example of getting a JSON string from a JsonDocument. I can get properties with RootElement.GetProperty("ItemName") and then call .GetString() but can't see a way to just get the root element as a JSON string?

Here an example:
JsonDocument jdoc = JsonDocument.Parse("{\"a\":123}");
using(var stream = new MemoryStream())
{
Utf8JsonWriter writer = new Utf8JsonWriter(stream, new JsonWriterOptions { Indented = true });
jdoc.WriteTo(writer);
writer.Flush();
string json = Encoding.UTF8.GetString(stream.ToArray());
}
For an easier usage you could put it in an extension method like:
public static string ToJsonString(this JsonDocument jdoc)
{
using (var stream = new MemoryStream())
{
Utf8JsonWriter writer = new Utf8JsonWriter(stream, new JsonWriterOptions { Indented = true });
jdoc.WriteTo(writer);
writer.Flush();
return Encoding.UTF8.GetString(stream.ToArray());
}
}
And use it like:
JsonDocument jdoc = JsonDocument.Parse("{\"a\":123}");
string json = jdoc.ToJsonString();

I have use RootElement to get a JsonElement and then call .ToString().
JsonDocument jdoc = JsonDocument.Parse("{\"a\":123}");
string json = jdoc.RootElement.ToString();

For the record there are 2 code snippets in official doco at How to serialize and deserialize (marshal and unmarshal) JSON in .NET
A. Use JsonDocument to write JSON
The following example shows how to write JSON from a JsonDocument:
(surprisingly long code snippet here)
The preceding code:
Reads a JSON file, loads the data into a JsonDocument, and writes formatted (pretty-printed) JSON to a file.
Uses JsonDocumentOptions to specify that comments in the input JSON are allowed but ignored.
When finished, calls Flush on the writer. An alternative is to let the writer autoflush when it's disposed.
B. Use Utf8JsonWriter
The following example shows how to use the Utf8JsonWriter class:
(...)
The snipped can be adjusted to use JsonDocument.Parse:
using var stream = new System.IO.MemoryStream();
using (var writer = new Utf8JsonWriter(stream, new JsonWriterOptions { Indented = true }))
{
var jsonDocument = JsonDocument.Parse(content);
jsonDocument.WriteTo(writer);
}
var formatted = System.Text.Encoding.UTF8.GetString(stream.ToArray());

Related

Convert a Stream into json value c#

I have below stream which I get from this line where req1 is of HttpResponseMessage type and responseMessage is of type Stream. How can I convert this Stream into a json Object. My end goal is to extract values from the specific keys in this json.
var responseMessage = await req1.Content.ReadAsStreamAsync();
Above answer has a class defined. I didnt want to define different class as my model is dynamic. I found this solution , which worked well and got me the desired result
var serializer = new JsonSerializer();
using (var sr = new StreamReader(responseMessage))
using (var jsonTextReader = new JsonTextReader(sr))
{
var jsObj= serializer.Deserialize(jsonTextReader);
}
try it
// read file into a string and deserialize JSON to a type
Movie movie1 = JsonConvert.DeserializeObject<Movie>(File.ReadAllText(#"c:\movie.json"));
// 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));
}

How to Save Large Json Data?

i have a large ObservableCollection that I want to get out as Json file.
I used the following code, But I get an error out of memory
string json = JsonConvert.SerializeObject(content, Formatting.Indented);
await File.WriteAllTextAsync("file.json");
How can I save this huge ObservableCollection in a json file?
Instead of serializing to a string, and then writing the string to a stream, stream it directly:
using var stream = File.Create("file.json");
JsonSerializer.Serialize(stream, content, new JsonSerializerOptions
{
WriteIdented = true
});
try to serialize directly to the file.This way Newtosoft https://www.newtonsoft.com/json/help/html/serializewithjsonserializertofile.htm recomends to do it
using (StreamWriter file = File.CreateText(#"c:\file.json"))
{
JsonSerializer serializer = new JsonSerializer();
serializer.Serialize(file, content);
}

Avoid XML Escape Double Quote

I'm currently trying to serialize a class into XML to be posted to php web service.
Whenever I did the normal serialization using XMLSerializer, XML declaration is always appear in the first line of the XML document (similar as to <?xml ....?>). I tested the XML and unable to get it working because the endpoint does not accept XML declaration and I can't do anything about it.
I'm unfamiliar with XML Serialization in C# to be honest.
Therefore, I used XMLWriter to do this as below :-
private string SerializeClassToString(GetRiskReport value)
{
var emptyNS = new XmlSerializerNamespaces(new[] { XmlQualifiedName.Empty });
var ser = new XmlSerializer(value.GetType());
var settings = new XmlWriterSettings();
settings.OmitXmlDeclaration = true;
using (var stream = new StringWriter())
{
using (var writer = XmlWriter.Create(stream, settings))
{
ser.Serialize(writer, value, emptyNS);
return stream.ToString();
}
}
}
Result for the Namespace is
<GetRiskReport FCRA=\"false\" ReturnResultsOnly=\"false\" Monitoring=\"false\">
... and I'm able to omit the XML Declaration, however I'm being introduced with 2 new problem.
I got \r\n for new line and I have escaped double quote such as ReturnResultsOnly=\"false\" Monitoring=\"false\" which is also unable processed by the endpoint.
I would like to ask is that does anyone can give me an idea on how to change the XmlWriterSetting to omit XML Declaration, avoid \r\n and also avoid escaped double quotes \"
Thanks for your advice in advance.
Simon
Try with following settings
settings.NewLineHandling = NewLineHandling.None;
settings.CheckCharacters = false;
private void SerializeClassToString(GetRiskReport value)
{
var emptyNS = new XmlSerializerNamespaces(new[]{XmlQualifiedName.Empty});
var ser = new XmlSerializer(value.GetType());
var settings = new XmlWriterSettings();
settings.OmitXmlDeclaration = true;
string path = 'your_file_path_here'
if (File.Exists(path)) File.Delete(path);
FileStream stream = File.Create(path);
using (var writer = XmlWriter.Create(stream, settings))
{
ser.Serialize(writer, value, emptyNS);
return;
}
}
There was no way to avoid ms bug or thier intensional specification about xmlserializing.It's easier and faster to use filestream object.

XmlSerializer Converts newlines

I'm trying to serialize an object to memory, pass it to another process as a string, and deserialize it.
I've discovered that the XML Serialization process strips the \r off of the newlines for strings in the object.
byte[] b;
// serialize to memory.
using (MemoryStream ms = new MemoryStream())
{
XmlSerializer xml = new XmlSerializer(this.GetType());
xml.Serialize(ms, this);
b = ms.GetBuffer();
}
// I can now send the bytes to my process.
Process(b);
// On the other end, I use:
using (MemoryStream ms = new MemoryStream(b))
{
XmlSerializer xml = new XmlSerializer(this.GetType());
clone = (myObject)xml.Deserialize(ms);
}
How do I serialize an object without serializing it to disk just like this, but without mangling the newlines in the strings?
The strings should be wrapped in CDATA sections to preserve the newlines.
The answer came from anther SO post, but I'm reposting it here because I had to tweak it a little.
I had to create a new class to manage XML read/write to memory stream. Here it is:
public class SafeXmlSerializer : XmlSerializer
{
public SafeXmlSerializer(Type type) : base(type) { }
public new void Serialize(StreamWriter stream, object o)
{
XmlWriterSettings ws = new XmlWriterSettings();
ws.NewLineHandling = NewLineHandling.Entitize;
using (XmlWriter xmlWriter = XmlWriter.Create(stream, ws))
{
base.Serialize(xmlWriter, o);
}
}
}
Since it is built on top of XmlSerializer, it should behave exactly as expected. It's just that when I serialize with a StreamWriter, I will use the "safe" version of the serialization, thus saving myself the headache.
I hope this helps someone else.

XmlSerializer - Encoding not supported

I have the following extension method to serialize my class....
public static string SerializeToXml<T>(this object obj)
{
XDocument doc = new XDocument();
XmlSerializer ser = new XmlSerializer(typeof(T));
using (var writer = doc.CreateWriter())
{
ser.Serialize(writer, obj);
}
return doc.ToString();
}
This seems to work fine and returns the following string for my serialized object:
<AuthenticatedUser xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<Username>mark</Username>
<UserID>4</UserID>
<Roles>
<string>AuthenticatedUsers</string>
</Roles>
<IsValid>false</IsValid>
</AuthenticatedUser>
However when I try to deserialize this string using the method below I get this error:
{"The encoding style '<AuthenticatedUser xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">\r\n <Username>mark</Username>\r\n <UserID>4</UserID>\r\n <Roles>\r\n <string>AuthenticatedUsers</string>\r\n </Roles>\r\n <IsMale>false</IsMale>\r\n</AuthenticatedUser>' is not valid for this call because this XmlSerializer instance does not support encoding. Use the SoapReflectionImporter to initialize an XmlSerializer that supports encoding."}
Method....
public static T DeserializeFromXml<T>(this string xml)
{
var element = XElement.Parse(xml);
XmlSerializer ser = new XmlSerializer(typeof(T));
using (var reader = element.CreateReader())
{
return (T)ser.Deserialize(reader, xml);
}
}
So after I read the error message I changed the deserialize method to use the SoadReflectionImporter....
public static T DeserializeFromXml<T>(this string xml)
{
var element = XElement.Parse(xml);
SoapReflectionImporter soap = new SoapReflectionImporter();
var mapping = soap.ImportTypeMapping(typeof(T));
XmlSerializer ser = new XmlSerializer(mapping);
using (var reader = element.CreateReader())
{
return (T)ser.Deserialize(reader, xml);
}
}
However I now get this error...
{"The encoding style '<AuthenticatedUser xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">\r\n <Username>mark</Username>\r\n <UserID>4</UserID>\r\n <Roles>\r\n <string>AuthenticatedUsers</string>\r\n </Roles>\r\n <IsValid>false</IsValid>\r\n</AuthenticatedUser>' is not valid for this call. Valid values are 'http://schemas.xmlsoap.org/soap/encoding/' for SOAP 1.1 encoding or 'http://www.w3.org/2003/05/soap-encoding' for SOAP 1.2 encoding."}
Does anyone know where I'm going wrong and how I can deserialize this string successfully?
The problem is the overload of the Deserialize method that you are calling:
return (T)ser.Deserialize(reader, xml);
The xml parameter in the call specifies the encoding style, but in this case you are passing the xml from the serialization. Simply delete the second parameter and just call Deserialize with the reader and it should work fine:
return (T)ser.Deserialize(reader);
XElement.CreateReader() doesn't return the XDeclaration.
Instead, try making an XmlReader from a StringReader.
Why are you using XmlSerializer ?
Unless you must control the way the output XML looks, you should be using DataContractSerializer
Here is a nice blog post about the two
Do you need the Parse(xml) call and the reader element? Since you have the string, can't you just deserialize the string? First convert to bytes...
byte [] bytes = Encoding.Unicode.GetBytes(xml);
MemoryStream mem = new MemoryStream(bytes);
returnValue = (T)ser.Deserialize(mem);

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