XML Webservice (ASMX) - SOAP Request and Response Invocation logging

You are an integration developer. Eventualy you came into the state where there is nothing else you can debug, and you have to check which SOAP request it is built on the request, and which SOAP response you are getting from the server.

C# XML Webservice (ASMX) - SOAP Request and Response Invocation logging

In the legaccy .NET framework System.Web.Services, this means using soapExtensions to help you intersept the interaction with the webservice. This is done like so:

 public class TraceExtension : SoapExtension
    {
        Stream oldStream;
        Stream newStream;
        string filename;

        // Save the Stream representing the SOAP request or SOAP response into 
        // a local memory buffer. 
        public override Stream ChainStream(Stream stream)
        {
            oldStream = stream;
            newStream = new MemoryStream();
            return newStream;
        }

        // When the SOAP extension is accessed for the first time, the XML Web 
        // service method it is applied to is accessed to store the file 
        // name passed in, using the corresponding SoapExtensionAttribute.   
        public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
        {
            return ((TraceExtensionAttribute)attribute).Filename;
        }

        // The SOAP extension was configured to run using a configuration file 
        // instead of an attribute applied to a specific XML Web service 
        // method. 
        public override object GetInitializer(Type WebServiceType)
        {
            // Return a file name to log the trace information to, based on the 
            // type. 
            //return "C:\\" + WebServiceType.FullName + ".log";
            return WebServiceType.FullName + ".log";
        }

        // Receive the file name stored by GetInitializer and store it in a 
        // member variable for this specific instance. 
        public override void Initialize(object initializer)
        {
            filename = (string)initializer;
        }

        //  If the SoapMessageStage is such that the SoapRequest or 
        //  SoapResponse is still in the SOAP format to be sent or received, 
        //  save it out to a file. 
        public override void ProcessMessage(SoapMessage message)
        {
            switch (message.Stage)
            {
                case SoapMessageStage.BeforeSerialize:
                    break;
                case SoapMessageStage.AfterSerialize:
                    WriteOutput(message);
                    break;
                case SoapMessageStage.BeforeDeserialize:
                    WriteInput(message);
                    break;
                case SoapMessageStage.AfterDeserialize:
                    break;
            }
        }

        public void WriteOutput(SoapMessage message)
        {
            newStream.Position = 0;
            FileStream fs = new FileStream(filename, FileMode.Append, FileAccess.Write);
            StreamWriter w = new StreamWriter(fs);

            string soapString = (message is SoapServerMessage) ? "SoapResponse" : "SoapRequest";
            w.WriteLine("-----" + soapString + " at " + DateTime.Now);
            w.Flush();
            Copy(newStream, fs);
            w.Close();
            newStream.Position = 0;
            Copy(newStream, oldStream);
        }

        public void WriteInput(SoapMessage message)
        {
            Copy(oldStream, newStream);
            FileStream fs = new FileStream(filename, FileMode.Append,
                FileAccess.Write);
            StreamWriter w = new StreamWriter(fs);

            string soapString = (message is SoapServerMessage) ?
                "SoapRequest" : "SoapResponse";
            w.WriteLine("-----" + soapString +
                " at " + DateTime.Now);
            w.Flush();
            newStream.Position = 0;
            Copy(newStream, fs);
            w.Close();
            newStream.Position = 0;
        }

        void Copy(Stream from, Stream to)
        {
            TextReader reader = new StreamReader(from);
            TextWriter writer = new StreamWriter(to);
            writer.WriteLine(reader.ReadToEnd());
            writer.Flush();
        }
    }

    // Create a SoapExtensionAttribute for the SOAP Extension that can be 
    // applied to an XML Web service method.
    [AttributeUsage(AttributeTargets.Method)]
    public class TraceExtensionAttribute : SoapExtensionAttribute
    {

        private string filename = "log.txt";
        private int priority;

        public override Type ExtensionType
        {
            get { return typeof(TraceExtension); }
        }

        public override int Priority
        {
            get { return priority; }
            set { priority = value; }
        }

        public string Filename
        {
            get
            {
                return filename;
            }
            set
            {
                filename = value;
            }
        }
    }

You activate the extension through app.config/web.config.

  <system.web>
    <webServices>
      <soapExtensionTypes>
        <add group="High" priority="1" type="emsEndpointTester.TraceExtension, emsEndpointTester" />
      </soapExtensionTypes>
    </webServices>

  </system.web>



Download SOURCE CODE with Sample Webservice