Windows Service Hosting WCF Objects over SSL (https) - Custom JSON Error Handling Doesn't Work
- by bpatrick100
I will first show the code that works in a non-ssl (http) environment. This code uses a custom json error handler, and all errors thrown, do get bubbled up to the client javascript (ajax).
// Create webservice endpoint
WebHttpBinding binding = new WebHttpBinding();
ServiceEndpoint serviceEndPoint = new ServiceEndpoint(ContractDescription.GetContract(Type.GetType(svcHost.serviceContract + ", " + svcHost.assemblyName)), binding, new EndpointAddress(svcHost.hostUrl));
// Add exception handler
serviceEndPoint.Behaviors.Add(new FaultingWebHttpBehavior());
// Create host and add webservice endpoint
WebServiceHost webServiceHost = new WebServiceHost(svcHost.obj, new Uri(svcHost.hostUrl));
webServiceHost.Description.Endpoints.Add(serviceEndPoint);
webServiceHost.Open();
I'll also show you what the FaultingWebHttpBehavior class looks like:
public class FaultingWebHttpBehavior : WebHttpBehavior
{
public FaultingWebHttpBehavior()
{
}
protected override void AddServerErrorHandlers(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
{
endpointDispatcher.ChannelDispatcher.ErrorHandlers.Clear();
endpointDispatcher.ChannelDispatcher.ErrorHandlers.Add(new ErrorHandler());
}
public class ErrorHandler : IErrorHandler
{
public bool HandleError(Exception error)
{
return true;
}
public void ProvideFault(Exception error, MessageVersion version, ref Message fault)
{
// Build an object to return a json serialized exception
GeneralFault generalFault = new GeneralFault();
generalFault.BaseType = "Exception";
generalFault.Type = error.GetType().ToString();
generalFault.Message = error.Message;
// Create the fault object to return to the client
fault = Message.CreateMessage(version, "", generalFault, new DataContractJsonSerializer(typeof(GeneralFault)));
WebBodyFormatMessageProperty wbf = new WebBodyFormatMessageProperty(WebContentFormat.Json);
fault.Properties.Add(WebBodyFormatMessageProperty.Name, wbf);
}
}
}
[DataContract]
public class GeneralFault
{
[DataMember]
public string BaseType;
[DataMember]
public string Type;
[DataMember]
public string Message;
}
The AddServerErrorHandlers() method gets called automatically, once webServiceHost.Open() gets called. This sets up the custom json error handler, and life is good :-)
The problem comes, when we switch to and SSL (https) environment. I'll now show you endpoint creation code for SSL:
// Create webservice endpoint
WebHttpBinding binding = new WebHttpBinding();
ServiceEndpoint serviceEndPoint = new ServiceEndpoint(ContractDescription.GetContract(Type.GetType(svcHost.serviceContract + ", " + svcHost.assemblyName)), binding, new EndpointAddress(svcHost.hostUrl));
// This exception handler code below (FaultingWebHttpBehavior) doesn't work with SSL communication for some reason, need to resarch...
// Add exception handler
serviceEndPoint.Behaviors.Add(new FaultingWebHttpBehavior());
//Add Https Endpoint
WebServiceHost webServiceHost = new WebServiceHost(svcHost.obj, new Uri(svcHost.hostUrl));
binding.Security.Mode = WebHttpSecurityMode.Transport;
binding.Security.Transport.ClientCredentialType = HttpClientCredentialType.None;
webServiceHost.AddServiceEndpoint(svcHost.serviceContract, binding, string.Empty);
Now, with this SSL endpoint code, the service starts up correctly, and wcf hosted objects can be communicated with just fine via client javascript. However, the custom error handler doesn't work. The reason is, the AddServerErrorHandlers() method never gets called when webServiceHost.Open() is run.
So, can anyone tell me what is wrong with this picture? And why, is AddServerErrorHandlers() not getting called automatically, like it does when I'm using non-ssl endpoints?
Thanks!
