Exporting a class with introductions

[ShadyG]

I seem to be having difficulties exporting a web service based on a class with aop introductions. Here's a sample config XML:

<object id="Mixin" type="PG.Service.Mixin, PG.Service"/>
<object id="PaGERService" type="Spring.Aop.Framework.ProxyFactoryObject, Spring.Aop">
  <property name="Target">
    <object type="PG.Service.PaGER, PG.Service"/>
  </property>
  <property name="IntroductionNames">
    <list>
      <value>Mixin</value>
    </list>
  </property>
</object>
<object id="PaGERWebService" type="Spring.Web.Services.WebServiceExporter, Spring.Web">
  <property name="TargetName" value="PaGERService"/>
  <property name="Namespace" value="(cannot post urls yet)"/>
</object>

I've tried it as above, with the target object separately-defined and referenced by ID, and via ObjectNameAutoProxyCreator (with the introduction named in the "InterceptorNames" list). In all cases, I get the same result at context load time:

[NotSupportedException: Cannot serialize interface Spring.Aop.Framework.IAopProxy.]
   System.Xml.Serialization.TypeDesc.CheckSupported() +76
   System.Xml.Serialization.TypeScope.GetTypeDesc(Type type, MemberInfo source, Boolean directReference, Boolean throwOnError) +308
   System.Xml.Serialization.TypeScope.GetTypeDesc(Type type) +36
   System.Xml.Serialization.XmlReflectionImporter.ImportMemberMapping(XmlReflectionMember xmlReflectionMember, String ns, XmlReflectionMember[] xmlReflectionMembers, Boolean rpc, Boolean openModel) +168
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel) +291

[InvalidOperationException: There was an error reflecting 'value'.]
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(XmlReflectionMember[] xmlReflectionMembers, String ns, Boolean hasWrapperElement, Boolean rpc, Boolean openModel) +1042
   System.Xml.Serialization.XmlReflectionImporter.ImportMembersMapping(String elementName, String ns, XmlReflectionMember[] members, Boolean hasWrapperElement, Boolean rpc, Boolean openModel, XmlMappingAccess access) +183
   System.Web.Services.Protocols.SoapReflector.ImportMembersMapping(XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, Boolean serviceDefaultIsEncoded, Boolean rpc, SoapBindingUse use, SoapParameterStyle paramStyle, String elementName, String elementNamespace, Boolean nsIsDefault, XmlReflectionMember[] members, Boolean validate, Boolean openModel, String key, Boolean writeAccess) +765
   System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +4263

[InvalidOperationException: Method PaGERWebService.Spring.Aop.Framework.ITargetAware.set_TargetProxy can not be reflected.]
   System.Web.Services.Protocols.SoapReflector.ReflectMethod(LogicalMethodInfo methodInfo, Boolean client, XmlReflectionImporter xmlImporter, SoapReflectionImporter soapImporter, String defaultNs) +10259
   System.Web.Services.Description.SoapProtocolReflector.ReflectMethod() +149
   System.Web.Services.Description.ProtocolReflector.ReflectBinding(ReflectedBinding reflectedBinding) +1980
   System.Web.Services.Description.ProtocolReflector.Reflect() +736
   System.Web.Services.Description.ServiceDescriptionReflector.ReflectInternal(ProtocolReflector[] reflectors) +501
   System.Web.Services.Description.ServiceDescriptionReflector.Reflect(Type type, String url) +165
   System.Web.Services.Protocols.DocumentationServerType..ctor(Type type, String uri) +213
   System.Web.Services.Protocols.DocumentationServerProtocol.Initialize() +390
   System.Web.Services.Protocols.ServerProtocol.SetContext(Type type, HttpContext context, HttpRequest request, HttpResponse response) +70
   System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +104

[InvalidOperationException: Unable to handle request.]
   System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type, HttpContext context, HttpRequest request, HttpResponse response, Boolean& abortProcessing) +337
   System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +236

[InvalidOperationException: Failed to handle request.]
   System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +431

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +0
   System.RuntimeMethodHandle.InvokeMethodFast(Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) +72
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) +371
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +29
   System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) +17
   Spring.Web.Services.WebServiceHandlerFactory.System.Web.IHttpHandlerFactory.GetHandler(HttpContext context, String requestType, String url, String path) in l:\projects\Spring.Net\src\Spring\Spring.Web\Web\Services\WebServiceHandlerFactory.cs:105
   System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, VirtualPath path, String pathTranslated, Boolean useAppConfig) +401
   System.Web.MapHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +183
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +191

Any thoughts? I guess I could understand if the introduced interface is not added to the public web service (though that would be great). But the mixin I'm using is only for internal use within the service implementation, so even if it's not exported I'd be happy.

[Mark Pollack]

Hi,

Not sure what is going on here off the top of my head, but you can explicitly list the list of interfaces in the exporter. That might help. See below.

<object id="PaGERWebService" type="Spring.Web.Services.WebServiceExporter, Spring.Web">
  <property name="TargetName" value="PaGERService"/>
  <property name="Namespace" value="(cannot post urls yet)"/>
  <property name=“Interfaces">
    <list> 
      <value>IPaGER, PG.Services.Interfaces</value>
    </list>
  </property>
</object>

There is also an JIRA issue to make many of the AOP classes serializable, so that might be related, I'll need to investigate more.

Cheers,
Mark

[Bruno Baia]

Hi,

Which version of Spring.NET are you using.
Anyway, like Mark said, explicitly list the list of interfaces in the exporter should work.

- Bruno

[ShadyG]

I feel like I'm closer now, thanks for the tip on listing out the interfaces. However, now that the full web service list is showing up, I'm having two new, distinct problems. Here's a concise version of my new XML:

  <object id="ServiceStatsAccumulator" type="PG.Service.ServiceStatsAccumulator, PG.Service"/>
  <object id="ServiceStatsReporter" type="PG.Service.ServiceStatsMixin, PG.Service"/>

  <object id="PaGERService" type="Spring.Aop.Framework.ProxyFactoryObject, Spring.Aop">
    <property name="Target">
      <object type="PG.Service.PaGER, PG.Service"/>
    </property>
    <property name="InterceptorNames">
      <list>
        <value>ServiceStatsAccumulator</value>
      </list>
    </property>
    <property name="IntroductionNames">
      <list>
        <value>ServiceStatsReporter</value>
      </list>
    </property>
  </object>

  <object id="PaGERWebService" type="Spring.Web.Services.WebServiceExporter, Spring.Web">
    <property name="TargetName" value="PaGERService"/>
    <property name="Namespace" value="..."/>
    <property name="Interfaces">
      <list>
        <value>PG.Contract.IPaGER, PG.Contract</value>
        <value>PG.Contract.IServiceStats, PG.Contract</value>
      </list>
    </property>
  </object>

When I hit any method that has not been introduced by IServiceStats (the "normal" methods of IPager), the accumulator fires correctly and attempts to cast the invocation.Target to IServiceStatsAdvice. Assuming the introduction has succeeded, I believe the cast should work (ServiceStatsMixin implements this interface), but I'm getting an InvalidCastException.

Second, when I hit the "GetServiceStats" method and try to access the mixed-in method to report on my accumulated stats, I get an error that reads "The HTTP verb POST used to access path '/PG.Web/PaGERWebService.asmx/PG.Contract.IServiceStats.GetServiceStats' is not allowed". Here it would appear that the method did indeed get introduced, but did not get wrapped as a web service method. Any idea what I'm doing wrong here?

For reference, I have tried wrapping the mixin class in a DefaultIntroductionAdvisor-inherited class. I have also tried listing the two interfaces in the "ProxyInterfaces" property of ProxyFactoryObject. I get the same results in all cases.

[Bruno Baia]

Hi,

I reproduced your pb, I'm investigating...

- Bruno

[Bruno Baia]

When I hit any method that has not been introduced by IServiceStats (the "normal" methods of IPager), the accumulator fires correctly and attempts to cast the invocation.Target to IServiceStatsAdvice. Assuming the introduction has succeeded, I believe the cast should work (ServiceStatsMixin implements this interface), but I'm getting an InvalidCastException.

invocation.Target returns the target object, here the instance of 'PG.Service.PaGER'. Use invocation.Proxy instead, you should be able to cast it as IServiceStatsAdvice.

Second, when I hit the "GetServiceStats" method and try to access the mixed-in method to report on my accumulated stats, I get an error that reads "The HTTP verb POST used to access path '/PG.Web/PaGERWebService.asmx/PG.Contract.IServiceStats.GetServiceStats' is not allowed". Here it would appear that the method did indeed get introduced, but did not get wrapped as a web service method. Any idea what I'm doing wrong here?

The proxy generated explicitly implements the introduction interface, that's why you got a method name prefixed by the full interface type name.
It seems the asmx web interface does not handle it very well, but if you create another project and reference it as a web reference, you will be able to call it.
Dots will be removed from the name. Method will be named 'PGContractIServiceStatsGetServiceStats'.

Anyway, if you still want to use the asmx interface, you can use the WebMethodAttribute and MessageName property :

<object id="PaGERWebService" type="Spring.Web.Services.WebServiceExporter, Spring.Web">
   <property name="TargetName" value="PaGERService"/>
   <property name="Namespace" value="..."/>
   <property name="MemberAttributes">
      <dictionary>
         <entry key="PG.Contract.IServiceStats.GetServiceStats">
            <object type="System.Web.Services.WebMethodAttribute, System.Web.Services">
               <property name="MessageName" value="GetServiceStats"/>
            </object>
        </entry>
      </dictionary>
   </property>
</object>

Cheers,
Bruno