I need to replace the DateTime serialization for JSON in WCF REST Self Hosted service. Right now, I'm using something like the following code to do it, but it's definitely not the way to go since it requires manipulating each class.
[DataContract]
public class Test
{
[IgnoreDataMember]
public DateTime StartDate;
[DataMember(Name = "StartDate")]
public string StartDateStr
{
get { return DateUtil.DateToStr(StartDate); }
set { StartDate = DateTime.Parse(value); }
}
}
where my utility function DateUtil.DateToStr does all the formatting work.
Is there any easy way to do it without having to touch the attributes on my classes which have the DataContract attribute? Ideally, there would be no attributes, but a couple of lines of code in my configuration to replace the serializer with one where I've overridden DateTime serialization.
Everything that I've found looks like I have to replace huge pieces of the pipeline.
This article doesn't appear to apply because in I'm using WebServiceHost not HttpServiceHost, which not part of the 4.5.1 Framework.
JSON.NET Serializer for WCF REST Services
By default WCF uses DataContractJsonSerializer to serialize data into JSON. Unfortunatelly date from this serializer is in very difficult format to parse by human brain.
"DateTime": "\/Date(1535481994306+0200)\/"
To override this behavior we need to write custom IDispatchMessageFormatter. This class will receive all data which should be returned to requester and change it according to our needs.
To make it happen to the operations in the endpoint add custom formatter - ClientJsonDateFormatter:
ServiceHost host=new ServiceHost(typeof(CustomService));
host.AddServiceEndpoint(typeof(ICustomContract), new WebHttpBinding(), Consts.WebHttpAddress);
foreach (var endpoint in host.Description.Endpoints)
{
if (endpoint.Address.Uri.Scheme.StartsWith("http"))
{
foreach (var operation in endpoint.Contract.Operations)
{
operation.OperationBehaviors.Add(new ClientJsonDateFormatter());
}
endpoint.Behaviors.Add(new WebHttpBehavior());
}
}
ClientJsonDateFormatter is simple class which just applies formatter ClientJsonDateFormatter
public class ClientJsonDateFormatter : IOperationBehavior
{
public void AddBindingParameters(OperationDescription operationDescription, BindingParameterCollection bindingParameters) { }
public void ApplyClientBehavior(OperationDescription operationDescription, ClientOperation clientOperation) { }
public void ApplyDispatchBehavior(OperationDescription operationDescription, DispatchOperation dispatchOperation)
{
dispatchOperation.Formatter = new ResponseJsonFormatter(operationDescription);
}
public void Validate(OperationDescription operationDescription) { }
}
In the formatter we took imput and serialize it with the changed Serializer:
public class ResponseJsonFormatter : IDispatchMessageFormatter
{
OperationDescription Operation;
public ResponseJsonFormatter(OperationDescription operation)
{
this.Operation = operation;
}
public void DeserializeRequest(Message message, object[] parameters)
{
}
public Message SerializeReply(MessageVersion messageVersion, object[] parameters, object result)
{
string json=Newtonsoft.Json.JsonConvert.SerializeObject(result);
byte[] bytes = Encoding.UTF8.GetBytes(json);
Message replyMessage = Message.CreateMessage(messageVersion, Operation.Messages[1].Action, new RawDataWriter(bytes));
replyMessage.Properties.Add(WebBodyFormatMessageProperty.Name, new WebBodyFormatMessageProperty(WebContentFormat.Raw));
return replyMessage;
}
}
And to send information to client we need data writer - RawDataWriter. Its implementation is simple:
class RawDataWriter : BodyWriter
{
byte[] data;
public RawDataWriter(byte[] data)
: base(true)
{
this.data = data;
}
protected override void OnWriteBodyContents(XmlDictionaryWriter writer)
{
writer.WriteStartElement("Binary");
writer.WriteBase64(data, 0, data.Length);
writer.WriteEndElement();
}
}
Applying all code will result in returning date in more friendly format:
"DateTime":"2018-08-28T20:56:48.6411976+02:00"
To show it in practice I created example in the github branch DateTimeFormatter.
Please check also this answer as very likely you also will need it.
There is a limitation in JSON to convert DateTime, specially according to your case.
Please see http://msdn.microsoft.com/en-us/library/bb412170(v=vs.110).aspx
and read the section Dates/Times and JSON
To resolve this problem, I simply changed the type of serialization from JSON to XML for all the calls including DateTime.
After long time discussion ,I have find out the solution for it.
Please Use the following Code to Solve serialized date..
[IgnoreDataMember]
public DateTime? PerformanceDate { get; set; }
[DataMember(EmitDefaultValue = false, Name = "PerformanceDate")]
public string UpdateStartDateStr
{
get
{
if (this.PerformanceDate.HasValue)
return this.PerformanceDate.Value.ToUniversalTime().ToString("s", CultureInfo.InvariantCulture);
else
return null;
}
set
{
// should implement this...
}
}
Related
Input JSON:
{ "name": "gerry" }
Action method:
{ public ActionResult GenerateQrCode([FromBody] string name }
Problem:
The simple-type args are null
ModelState: Invalid
The built-in json deserializer can't handle the input in this form
I've tried:
ConfigureServices() -> services.AddControllersWithViews().AddNewtonsoftJson(); to switch to NewtonSoft, which I know/love
I've set a break-point into the non-NewtonSoft built-in MS SystemTextJsonInputFormatter.ctor() just to check, if it's still used: yes, it is, I'm not sure why, when I'm calling the above .AddNewtonsoftJson()
The situation:
The client POSTs all the input params as one JSON string document, which is UTF8 w/out BOM
The string comes in at the server-side and is nicely readable with new System.IO.StreamReader(Request.Body).ReadToEnd() from inside the immediate window
I need a way ASP.NET Core deserializes this, as it was able under the .NET4.X for many years w/out any issue
I wouldn't like to add [FromBody] and similar opt-in signatures all over the server actions/args
You pass the name as json but accept as a string so it will be null, you can use an InputFormatter like:
public class RawJsonBodyInputFormatter : InputFormatter
{
public RawJsonBodyInputFormatter()
{
this.SupportedMediaTypes.Add("application/json");
}
public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context)
{
var request = context.HttpContext.Request;
using (var reader = new StreamReader(request.Body))
{
var content = await reader.ReadToEndAsync();
return await InputFormatterResult.SuccessAsync(content);
}
}
protected override bool CanReadType(Type type)
{
return type == typeof(string);
}
}
In startup.cs:
services
.AddMvc(options =>
{
options.InputFormatters.Insert(0, new RawJsonBodyInputFormatter());
});
And then you can get the row string
To deserilize it, you can check this, use Newtonsoft and make the string to a Model
[HttpPost]
public IActionResult GenerateQrCode([FromBody] string name)
{
object o = JsonConvert.DeserializeObject(name);
MyModel my = JsonConvert.DeserializeObject<MyModel>(o.ToString());
return View();
}
I'm currently working on a project where I need to fetch a large amount of data from the Database and parse it into a specific Json format, I already have built my custom Serializers and Its working properly when i pass a List to Gson. But as I was already working with Streams from my JPA Layer, I thought I could pass the Stream down to the Gson parser so that it could transform it directly to my Json data. But I'm getting an empty Json object instead of a correctly populated one.
So, if anyone could point to me a way to make Gson work with Java 8 Streams or if this isn't possible currently.. i could not find anything on Google, so i came to Stackoverflow.
You could use JsonWriter to streaming your data to output stream:
public void writeJsonStream(OutputStream out, Stream<DataObject> data) throws IOException {
try(JsonWriter writer = new JsonWriter(new OutputStreamWriter(out, "UTF-8"))) {
writer.setIndent(" ");
writer.beginArray();
data.forEach(d -> {
d.beginObject();
d.name("yourField").value(d.getYourField());
....
d.endObject();
});
writer.endArray();
}
}
Note that you're in charge of controling the json structure.
That is, if your DataObject contains nested Object, you have to write beginObject()/endObject() respectively. The same goes for nested array.
It is not as trivial as one would expect, but it can be done in a generic way.
When you look into the Javadoc to TypeAdapterFactory, they provide a very simplistic way of writing a TypeAdapterFactory for a custom type. Alas, it does not work as expected because of problems with element type detection. The proper way to do this can be found in Gson-internal CollectionTypeAdapterFactory. It is quite complex, but taking what's necessary one can come up with something like that:
final class StreamTypeAdapterFactory implements TypeAdapterFactory {
#SuppressWarnings("unchecked")
#Override
public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> typeToken) {
Type type = typeToken.getType();
Class<? super T> rawType = typeToken.getRawType();
if (!Stream.class.isAssignableFrom(rawType)) {
return null;
}
Type elementType = ExtraGsonTypes.getStreamElementType(type, rawType);
TypeAdapter<?> elementAdapter = gson.getAdapter(TypeToken.get(elementType));
return (TypeAdapter<T>) new StreamTypeAdapter<>(elementAdapter);
}
private static class StreamTypeAdapter<E> extends TypeAdapter<Stream<E>> {
private final TypeAdapter<E> elementAdapter;
StreamTypeAdapter(TypeAdapter<E> elementAdapter) {
this.elementAdapter = elementAdapter;
}
public void write(JsonWriter out, Stream<E> value) throws IOException {
out.beginArray();
for (E element : iterable(value)) {
elementAdapter.write(out, element);
}
out.endArray();
}
public Stream<E> read(JsonReader in) throws IOException {
Stream.Builder<E> builder = Stream.builder();
in.beginArray();
while (in.hasNext()) {
builder.add(elementAdapter.read(in));
}
in.endArray();
return builder.build();
}
}
private static <T> Iterable<T> iterable(Stream<T> stream) {
return stream::iterator;
}
}
The ExtraGsonTypes is a special class that I used to circumvent package-private access to $Gson$Types.getSupertype method. It's a hack that works if you're not using JDK 9's modules - you simply place this class in the same package as $Gson$Types:
package com.google.gson.internal;
import java.lang.reflect.*;
import java.util.stream.Stream;
public final class ExtraGsonTypes {
public static Type getStreamElementType(Type context, Class<?> contextRawType) {
return getContainerElementType(context, contextRawType, Stream.class);
}
private static Type getContainerElementType(Type context, Class<?> contextRawType, Class<?> containerSupertype) {
Type containerType = $Gson$Types.getSupertype(context, contextRawType, containerSupertype);
if (containerType instanceof WildcardType) {
containerType = ((WildcardType)containerType).getUpperBounds()[0];
}
if (containerType instanceof ParameterizedType) {
return ((ParameterizedType) containerType).getActualTypeArguments()[0];
}
return Object.class;
}
}
(I filed an issue about that in GitHub)
You use it in the following way:
Gson gson = new GsonBuilder()
.registerTypeAdapterFactory(new StreamTypeAdapterFactory())
.create();
System.out.println(gson.toJson(Stream.of(1, 2, 3)));
First off my question is very similar to below however I'm not sure if the answers are applicable to my specific problem or whether I just need clarification about how to approach it:
Convert LinkedHashMap<String,String> to an object in Java
I am using struts2 json rest plugin to convert a json array into a java array. The array is sent through an ajax post request and the java receives this data. However instead of being the object type I expect it is received as a LinkedHashmap. Which is identical to the json request in structure.
[
{advance_Or_Premium=10000, available=true},
{advance_Or_Premium=10000, available=true},
{advance_Or_Premium=10000, available=true}
]
The data is all present and correct but just in the wrong type. Ideally I want to send the data in my object type or if this is not possible convert the LinkedHashMap from a list of keys and values into the object array. Here is the class I am using, incoming data is received in the create() method:
#Namespace(value = "/rest")
public class OptionRequestAction extends MadeAbstractAction implements ModelDriven<ArrayList<OptionRequestRest>>
{
private String id;
ArrayList<OptionRequestRest> model = new ArrayList<OptionRequestRest>();
public HttpHeaders create()
{
// TODO - need to use model here but it's a LinkedHashmap
return new DefaultHttpHeaders("create");
}
public String getId()
{
return this.id;
}
public ArrayList<OptionRequestRest> getModel()
{
return this.model;
}
public ArrayList<OptionRequestRest> getOptionRequests()
{
#SuppressWarnings("unchecked")
ArrayList<OptionRequestRest> lReturn = (ArrayList<OptionRequestRest>) this.getSession().get("optionRequest");
return lReturn;
}
// Handles /option-request GET requests
public HttpHeaders index()
{
this.model = this.getOptionRequests();
return new DefaultHttpHeaders("index").lastModified(new Date());
}
public void setId(String pId)
{
this.id = pId;
}
public void setModel(ArrayList<OptionRequestRest> pModel)
{
this.model = pModel;
}
// Handles /option-request/{id} GET requests
public HttpHeaders show()
{
this.model = this.getOptionRequests();
return new DefaultHttpHeaders("show").lastModified(new Date());
}
}
One of the things which is confusing me is that this code works fine and returns the correct object type if the model is not an array. Please let me know if my question is not clear enough and needs additional information. Thanks.
Is there a way to make DataContractJsonSerializer emit the "odata.type" field required when posting an OData entity into a collection that supports multiple entity types (hierarchy per table)?
If I construct DataContractJsonSerializer with a settings object with EmitTypeInformation set to Always, it emits a "__type" field in the output, but that's not the field name needed for OData and the format of the value is wrong as well.
Is there any way to hook into the DataContractJsonSerializer pipeline to inject the desired "odata.type" field into the serialization output?
It would be such a hack to have to parse the serialization output in order to inject the field. How does WCF Data Services do it? Not using DataContractJsonSerializer is my guess.
Have you considered using Json.Net? Json.Net is much more extensible and the scenario that you have can be done using a custom resolver. sample code
class Program
{
static void Main(string[] args)
{
Console.WriteLine(
JsonConvert.SerializeObject(new Customer { Name = "Raghu" }, new JsonSerializerSettings
{
ContractResolver = new CustomContractResolver()
}));
}
}
public class CustomContractResolver : DefaultContractResolver
{
protected override JsonObjectContract CreateObjectContract(Type objectType)
{
JsonObjectContract objectContract = base.CreateObjectContract(objectType);
objectContract.Properties.Add(new JsonProperty
{
PropertyName = "odata.type",
PropertyType = typeof(string),
ValueProvider = new StaticValueProvider(objectType.FullName),
Readable = true
});
return objectContract;
}
private class StaticValueProvider : IValueProvider
{
private readonly object _value;
public StaticValueProvider(object value)
{
_value = value;
}
public object GetValue(object target)
{
return _value;
}
public void SetValue(object target, object value)
{
throw new NotSupportedException();
}
}
}
public class Customer
{
public string Name { get; set; }
}
I can't answer your first two questions, but for the third question, I found on the OData Team blog a link to the OData WCF Data Services V4 library open source code. Downloading that code, you will see that they perform all serialization and deserialization manually. They have 68 files in their two Json folders! And looking through the code they have comments such as:
// This is a work around, needTypeOnWire always = true for client side:
// ClientEdmModel's reflection can't know a property is open type even if it is, so here
// make client side always write 'odata.type' for enum.
So that to me kind of implies there is no easy, clean, simple, elegant way to do it.
I tried using a JavaScriptConverter, a dynamic type, and other stuff, but most of them ended up resorting to using Reflection which just made for a much more complicated solution versus just using a string manipulation approach.
I have structure IntEx - in short it extends normal Int32 and processed operation. It looks like this:
[Serializable]
public struct IntEx
{
private int internalValue;
private IntEx(int value)
{
internalValue = value;
}
public static implicit operator int(IntEx value)
{
return value.internalValue;
}
public static implicit operator IntEx(int value)
{
return new IntEx(value);
}
}
If we send this structure through WCF it serialize using JSON and output will "nicely look". Like we will use sample code below:
DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(TestClass));
using (MemoryStream stream = new MemoryStream())
{
jsonSerializer.WriteObject(stream, testClass);
string serializedString = Encoding.UTF8.GetString(stream.GetBuffer());
Console.WriteLine("JSON: {0}", serializedString);
}
public class TestClass
{
public int I1 { get; set; }
public IntEx I2 { get; set; }
}
Output look like this
JSON: {"I1":11,"I2":{"internalValue":22}}
Client and other "third-part" progam use this format (with internalValue).
Using IntEx is widely use in my application. One of the object is serialized to XML (some kind of setting). This object use IntEx as type.
So I have to implement IXmlSerializable to structure IntEx, because without this property is serialized like empty node
XML: <TestClass><I1>11</I1><I2 /></TestClass>
If I change IntEx to use IXmlSerializable
[Serializable]
public struct IntEx : IXmlSerializable
{
private int internalValue;
private IntEx(int value)
{
internalValue = value;
}
public static implicit operator int(IntEx value)
{
return value.internalValue;
}
public static implicit operator IntEx(int value)
{
return new IntEx(value);
}
System.Xml.Schema.XmlSchema IXmlSerializable.GetSchema()
{
return null;
}
void IXmlSerializable.ReadXml(System.Xml.XmlReader reader)
{
throw new NotImplementedException();
}
void IXmlSerializable.WriteXml(System.Xml.XmlWriter writer)
{
writer.WriteValue(internalValue);
}
}
XML output look ok
XML: <TestClass><I1>11</I1><I2>22</I2></TestClass>
but all my service break down, since now JSON look like this:
JSON: {"I1":11,"I2":"<IntEx xmlns=\"http:\/\/schemas.datacontract.org\/2004\/07\/TestJSONSerialization\">22<\/IntEx>"}
I read that if you use IXmlSerializable, JSON serialization "think" that I'm responsible for serialize so leave this object to me... But how can I change back to "original" serialization.
So now I'm in deadend... I need JSON output look like before, but I also need to some how force to write setting to XML with two conditions:
internalValue should remain private - it shouldn't be accessible using some public Property
I don't want rewrite bunch of code to chaneg (use boxing for JSON's properties) or change all possible property or class that can be saved to XML file.
So can anyone give me some clue, how I can resolve this issue? :/
you can use DataContractJsonSerializer with IDataContractSurrogate. using the IDataContractSurrogate to convert "IntEx" to "IntExJson", and the "IntExJson" don't need to inherit from IXmlSerializable.
IDataContractSurrogate can be used to remove some features from object, and convert to the similar object. and then use:
public DataContractJsonSerializer(Type type, IEnumerable<Type> knownTypes, int maxItemsInObjectGraph, bool ignoreExtensionDataObject, IDataContractSurrogate dataContractSurrogate, bool alwaysEmitTypeInformation);
to serialize the object to json. the deserialization is same.