I am trying to consume a REST API to Get data by httpclient, encountered a parsing problem ,{"Error in line 1 position 95. Expecting element 'workflow' from namespace 'http://schemas.datacontract.org/2004/07/'.. Encountered 'Element' with name 'workflow', namespace ''. "}
the client code is
string baseUri = "/rest/workflows/";
client = CreateClient(baseUri);
HttpRequestMessage request = CreateRequest(baseUri);
var task = client.SendAsync(request);
HttpResponseMessage response = task.Result;
response.EnsureSuccessStatusCode();
response.Content.ReadAsAsync<collection>().ContinueWith(wf =>
{
Console.WriteLine(wf.Result.workflow.Length);
});
the data classes
/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("xsd", "4.0.30319.17929")]
[System.SerializableAttribute()]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "http://www.w3.org/2005/Atom", IsNullable = false)]
public partial class collection
{
private workflow[] workflowField;
/// <remarks/>
[System.Xml.Serialization.XmlElementAttribute("workflow", Form = System.Xml.Schema.XmlSchemaForm.Unqualified)]
public workflow[] workflow
{
get
{
return this.workflowField;
}
set
{
this.workflowField = value;
}
}
}
and the response xml file is in this format
<collection xmlns:ns2="http://www.w3.org/2005/Atom">
<workflow uuid="5ffbde8c-c430-4851-9c83-164c102a4d68">
<name>Remove a Volume</name>
<categories>
<category>Decommissioning</category>
</categories>
</workflow>
</collection>
I can get the string by using response.Content.ReadAsStringAsync() and save it to xml file, then ,i deserilize it to collection,can succeed ,but need and a default namespace to the serizliazer
XmlSerializer serializer = new XmlSerializer(typeof(collection), "xmlns:ns2=\"http://www.w3.org/2005/Atom\"");
c = serializer.Deserialize(stream) as collection;
anyone can help on this
You should not touch the generated file from xsd.exe tool.
Just explicitly set that you want to use the XmlSerializer instead of the DataContractSerializer used by default with XmlMediaTypeFormatter by setting UseXmlSerializer = true.
So you must create a specific type formatter like this :
var formatters = new List<MediaTypeFormatter>() {
new XmlMediaTypeFormatter(){ UseXmlSerializer = true } };
And use it as a parameter of the ReadAsAsync method :
private async Task<T> ReadAsync<T>(HttpResponseMessage response)
=> await response.Content.ReadAsAsync<T>(formatters);
Your namespaces do not match; your xml declares a namespace alias (ns2) for the atom address, but the namespace of the collection element is still empty, since it doesn't use that alias (it is not ns2:collection). Either the xml is wrong or the code is. If the xml cannot be changed, then simply set the namespace on the [XmlRoot(...)] to be the empty string. If the C# is correct and the xml is wrong, then make it the namespace instead of an alias:
<collection xmlns="http://www.w3.org/2005/Atom">
<workflow uuid="5ffbde8c-c430-4851-9c83-164c102a4d68">
<name>Remove a Volume</name>
<categories>
<category>Decommissioning</category>
</categories>
</workflow>
</collection>
or identically:
<ns2:collection xmlns:ns2="http://www.w3.org/2005/Atom">
<workflow uuid="5ffbde8c-c430-4851-9c83-164c102a4d68">
<name>Remove a Volume</name>
<categories>
<category>Decommissioning</category>
</categories>
</workflow>
</ns2:collection>
I had the exact same issue when reading data from my web api. What solved the issue for me is to decorate the class in the client with the [DataContract(Namespace="namespacefromyourwebapi")] attribute and for each property in your class decorate it with the [DataMember] attribute.
Related
I want to programmatically set the paths on a rest service. I have this bean method which has all the paths.
public List<String> getSubscribeChannelsForRest() { .. }
This is the rest service
#RestController
public class RestMessageController {
#PostMapping(
path = { "#{somebean.getSubscribeChannelsForRest()[0]}",
"#{somebean.getSubscribeChannelsForRest()[1]}",
"#{somebean.getSubscribeChannelsForRest()[2]}"
})
public String processMessage(#RequestBody String messageBody, HttpServletRequest request) { .. }
The above code works but I want to avoid hard coding the array numbers. There is what I tried.
#PostMapping(
path = { "#{somebean.getSubscribeChannelsForRest()}",
This doesn't work because the spring method RequestMappingHandlerMapping.resolveEmbeddedValuesInPatterns(String[] patterns) takes the above SpEL as a single element array. I've checked the trace logs and all the element in the given list get concatenated .
i've detected a strange behavior calling a WCF Service from a Powershell script. Using the command 'New-WebServiceProxy' from Powershell 2.0 get's you the abillity to send requests to a Webservice from a PS script. But i got some problems with System.DateTime objects on the service side, the value on the server side is always DateTime.Min.
So i created a small test service an script and i can reproduce this error. I used a 'standard' WCF-Project from VS2010 and extedended the 'DataContract' Class with a DateTime Property:
[DataContract]
public class CompositeType
{
bool boolValue = true;
string stringValue = "Hello ";
[DataMember]
public bool BoolValue
{
get { return boolValue; }
set { boolValue = value; }
}
[DataMember]
public string StringValue
{
get { return stringValue; }
set { stringValue = value; }
}
[DataMember]
public DateTime Datum { get; set; }
}
Powershell script to call the service:
cls
$serv = New-WebServiceProxy -uri 'http://localhost:50176/TestService.svc?wsdl' - Namespace wt
$data = [wt.CompositeType](New-Object wt.CompositeType)
$data.StringValue = "abcd"
$data.BoolValue = $true
$data.Datum = Get-Date
$serv.GetDataUsingDataContract($data)
If needed, i can send you a dropbox link for the zipped project.
Regards Uwe
I've never used powershell before but thought I'd take a long overdue look at it for this question!
The proxy object $data can have a date property set but, despite what your code looks like its doing, $data isn't the real object, just an XML proxy of it.
If you enter command "$data" you'll see what looks like an XmlSerialized version of the object (has xxSpecified properties for the bool and DateTime). It does reflect changes made by e.g. "$data.Datum = Get-Date".
The proxy is deserialised back to an instance of MyCompositeType when you call GetUsingDataContract (as its passed as a parameter and sent using XML) which you can see by putting breakpoints on the property get/setters prior to calling it.
As part of this deserialization, only the StringValue makes it which is because the Xml serialization for the other properties will only include values where "xxxSpecified" is true.
If you set the "xxxSpecified" properties in the proxy they will serialize back correctly.
But the best fix is to change their DataMember attribute to:
[DataMember(IsRequired=true)]
Which should just work with the code you've got.
I am extending WebHttpBehavior to expose a WCF REST service with customized serialization and deserialization (plus a certain number of other features that are not relevant to the problem).
The new behavior uses an implementation of IDispatchMessageFormatter to perform custom serialization and deserialization of POCOs served by the service and sent to it thanks to the SerializeReply and DeserializeRequest methods.
I can serve XML and JSON exactly how I need them in SerializeReply.
I can deserialize XML without a problem, however I can't seem to find the way to deserialize a JSON message because I can't obtain the plain text contained in the Message parameter of DeserializeRequest.
This is what the code in DeserializeRequest looks like right now:
if (format == System.ServiceModel.Web.WebMessageFormat.Json)
{
var data = ""; // TODO obtain plain text from Message object
var json = JsonConvert.DeserializeObject(data, paramType, new IsoDateTimeConverter(), new StringEnumConverter());
parameters[paramIndex] = json;
}
else
{
var serializer = new System.Xml.Serialization.XmlSerializer(paramType, string.Empty);
var reader = message.GetReaderAtBodyContents();
parameters[paramIndex] = serializer.Deserialize(reader);
}
I'm using Json.NET for JSON (de)serialization.
Any suggestions on how to obtain plain text from the Message object in order to deserialize it would be greatly appreciated.
If you think there's something wrong in my approach I'd also like to hear of it in the comments.
You need to make sure that the WebMessageFormat of the Message is set to Raw, otherwise WCF will use a the JsonMessageEncoder in order to create the Message which in turn won't allow you to get to the raw message content.
You do that by implementing a custom WebContentTypeMapper:
public class RawMapper : WebContentTypeMapper
{
public override WebContentFormat GetMessageFormatForContentType(string contentType)
{
return WebContentFormat.Raw;
}
}
...which needs to be applied to the WebHttpBinding:
webHttpBinding.ContentTypeMapper = new RawMapper();
..or via configuration:
<bindings>
<webHttpBinding>
<binding contentTypeMapper="Samples.RawMapper, MyContentTypeMapperAssembly, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
</webHttpBinding>
</bindings>
With that in place, you can then retrieve the request body as a String like that:
public void DeserializeRequest(Message message, object[] parameters)
{
var bodyReader = message.GetReaderAtBodyContents();
bodyReader.ReadStartElement("Binary");
byte[] rawBody = bodyReader.ReadContentAsBase64();
string messageAsString;
using (var reader = new StreamReader(new MemoryStream(rawBody)))
messageAsString = reader.ReadToEnd();
object jsonObj = JsonConvert.DeserializeObject(messageAsString);
parameters[0] = jsonObj;
}
Even if you are using WebMessageFormat.Json you can convert your message to string and then deserialize it to object inside DeserializeRequest method.
MemoryStream mss = new MemoryStream();
XmlDictionaryWriter writer = JsonReaderWriterFactory.CreateJsonWriter(mss);
message.WriteMessage(writer);
writer.Flush();
string messageBody = Encoding.UTF8.GetString(mss.ToArray());
var obj = JsonConvert.DeserializeObject(messageBody, operation.Messages[0].Body.Parts[0].Type);
parameters[0] = obj;
I'm trying to consume twitter's REST api mentioned at this link using WCF REST starter kit mentioned at this link.
I'm using the same objects in DataContract as mentioned in the article - statusList and status.
[assembly: ContractNamespace("", ClrNamespace = "TwitterShell")]
[CollectionDataContract(Name = "statuses", ItemName = "status")]
public class statusList : List<status> { }
public class user
{
public string id;
public string name;
public string screen_name;
}
public class status
{
public string id;
public string text;
public user user;
}
I'm reading the XML contents using ReadAsDataContract() method.
HttpClient http = new HttpClient("http://twitter.com/statuses/");
http.TransportSettings.Credentials =
new NetworkCredential("{username}", "{password}");
HttpResponseMessage resp = http.Get("friends_timeline.xml");
resp.EnsureStatusIsSuccessful();
statusList sList = resp.Content.ReadAsDataContract<statusList>();
And I get the following exception. I have not defined the following namespace at all.
Error in line 1 position 24. Expecting element 'statuses' from namespace 'http://schemas.datacontract.org/2004/07/sitename'.. Encountered 'Element' with name 'statuses', namespace ''.
Please help. Thanks.
Just don't do it. You are in for a world of pain if you try using Datacontracts and operation contracts to access non-wcf services.
Ok, so I guess that was a bit unfair leaving you high and dry without an alternative, so try this:
var response = client.Get("http://twitter.com/statuses/friends_timeline.xml");
var statuses = response.Content.ReadAsXElement();
var statusQuery = from st in statuses.Elements("status")
select new status {
id = st.Element("id").Value,
text = st.Element("text").Value,
user = (from us in st.Elements("user")
select new user {
id = us.Element("id").Value,
name = us.Element("name").Value,
screen_name = us.Element("screen_name").Value
}).FirstOrDefault()
};
var statuses = statusQuery.ToList();
Using Linq to XML to create objects from the XML document allows you to avoid the magic of serializers and completely control the names and datatypes of your client side objects. It would be really easy to wrap this as a new HttpContent extension method so that you could simply do:
var statuses = response.Content.ReadAsTwitterStatuses();
I came across your post searching for answers to the same problem and I was able to find a solution for what you are looking for if you want to forgo the LINQ to XML approach.
1) Make sure you annotate your Status class with the following decoration
[DataContract (Namespace = "")]
By specifying the above annotation, you are overriding the namespace from the default namespace of your class. This should fix your namespace problem.
2) To address the issues of nulls (which I also experienced), order of your fields are very important. When your objects are deserialized, it is done in alphabetically order. You can order your fields to match the order of the incoming XML using the Order property on the DataMember annotation.
e.g.
[DataMember (Order = 1)]
public string text
etc ...
I am having a minor problem with WCF service proxies where the message contains List<string> as a parameter.
I am using the 'Add Service reference' in Visual Studio to generate a reference to my service.
// portion of my web service message
public List<SubscribeInfo> Subscribe { get; set; }
public List<string> Unsubscribe { get; set; }
These are the generated properties on my MsgIn for one of my web methods.
You can see it used ArrayOfString when I am using List<string>, and the other takes List<SubscribeInfo> - which matches my original C# object above.
[System.Runtime.Serialization.DataMemberAttribute(EmitDefaultValue=false)]
public System.Collections.Generic.List<DataAccess.MailingListWSReference.SubscribeInfo> Subscribe {
get {
return this.SubscribeField;
}
set {
if ((object.ReferenceEquals(this.SubscribeField, value) != true)) {
this.SubscribeField = value;
this.RaisePropertyChanged("Subscribe");
}
}
}
[System.Runtime.Serialization.DataMemberAttribute(EmitDefaultValue=false)]
publicDataAccess.MailingListWSReference.ArrayOfString Unsubscribe {
get {
return this.UnsubscribeField;
}
set {
if ((object.ReferenceEquals(this.UnsubscribeField, value) != true)) {
this.UnsubscribeField = value;
this.RaisePropertyChanged("Unsubscribe");
}
}
}
The ArrayOfString class generated looks like this. This is a class generated in my code - its not a .NET class. It actually generated me a class that inherits from List, but didn't have the 'decency' to create me any constructors.
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "3.0.0.0")]
[System.Runtime.Serialization.CollectionDataContractAttribute(Name="ArrayOfString", Namespace="http://www.example.com/", ItemName="string")]
[System.SerializableAttribute()]
public class ArrayOfString : System.Collections.Generic.List<string> {
}
The problem is that I often create my message like this :
client.UpdateMailingList(new UpdateMailingListMsgIn()
{
Email = model.Email,
Name = model.Name,
Source = Request.Url.ToString(),
Subscribe = subscribeTo.ToList(),
Unsubscribe = unsubscribeFrom.ToList()
});
I really like the clean look this gives me.
Now for the actual problem :
I cant assign a List<string> to the Unsubscribe property which is an ArrayOfString - even though it inherits from List. In fact I cant seem to find ANY way to assign it without extra statements.
I've tried the following :
new ArrayOfString(unsubscribeFrom.ToList()) - this constructor doesn't exist :-(
changing the type of the array used by the code generator - doesn't work - it always gives me ArrayOfString (!?)
try to cast List<string> to ArrayOfString - fails with 'unable to cast', even though it compiles just fine
create new ArrayOfString() and then AddRange(unsubscribeFrom.ToList()) - works, but I cant do it all in one statement
create a conversion function ToArrayOfString(List<string>), which works but isn't as clean as I want.
Its only doing this for string, which is annoying.
Am i missing something? Is there a way to tell it not to generate ArrayOfString - or some other trick to assign it ?
Any .NET object that implements a method named "Add" can be initialized just like arrays or dictionaries.
As ArrayOfString does implement an "Add" method, you can initialize it like this:
var a = new ArrayOfString { "string one", "string two" };
But, if you really want to initialize it based on another collection, you can write a extension method for that:
public static class U
{
public static T To<T>(this IEnumerable<string> strings)
where T : IList<string>, new()
{
var newList = new T();
foreach (var s in strings)
newList.Add(s);
return newList;
}
}
Usage:
client.UpdateMailingList(new UpdateMailingListMsgIn()
{
Email = model.Email,
Name = model.Name,
Source = Request.Url.ToString(),
Subscribe = subscribeTo.ToList(),
Unsubscribe = unsubscribeFrom.To<ArrayOfString>()
});
I prefer not to return generic types across a service boundary in the first place. Instead return Unsubscribe as a string[], and SubscriptionInfo as SubscriptionInfo[]. If necessary, an array can easily be converted to a generic list on the client, as follows:
Unsubscribe = new List<string>(unsubscribeFrom);
Subscribe = new List<SubscriptionInfo>(subscribeTo);
Too late but can help people in the future...
Use the svcutil and explicitly inform the command line util that you want the proxy class to be serialized by the XmlSerializer and not the DataContractSerializer (default). Here's the sample:
svcutil /out:c:\Path\Proxy.cs /config:c:\Path\Proxy.config /async /serializer:XmlSerializer /namespace:*,YourNamespace http://www.domain.com/service/serviceURL.asmx
Note that the web service is an ASP.NET web service ok?!
If you are using VS 2008 to consume service then there is an easy solution.
Click on the "Advanced..." button on the proxy dialog that is displayed when you add a Service Reference. In the Collection Type drop down you can select System.Generic.List. The methods returning List should now work properly.
(Hope this is what you were asking for, I'm a little tired and the question was a tad difficult for me to read.)