HOW TO：實作 SOAP 擴充功能
本主題專門說明舊有技術。 應該使用下列建立 XML Web Service 及 XML Web Service 用戶端： Windows Communication Foundation.
下列程式碼範例是一個 SOAP 擴充功能，這個 SOAP 擴充功能會記錄往返傳送於 Web 服務或 Web 服務用戶端的 SOAP 訊息。如果安裝下列 SOAP 擴充功能是為了要搭配 Web 服務一起執行，ASPNET 使用者帳戶就必須擁有可以寫入記錄檔所在目錄的權限。
**注意：**這個特定 SOAP 擴充功能並不會修改 SOAP 訊息。因此，不需要對稱地在用戶端和伺服器上實作這個擴充功能。
範例
Imports System
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.IO
' Define a SOAP Extension that traces the SOAP request and SOAP response
' for the Web service method the SOAP extension is applied to.
Public Class TraceExtension
Inherits SoapExtension
Private oldStream As Stream
Private newStream As Stream
Private m_filename As String
' Save the Stream representing the SOAP request or SOAP response into
' a local memory buffer.
Public Overrides Function ChainStream(stream As Stream) As Stream
oldStream = stream
newStream = New MemoryStream()
Return newStream
End Function
' 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 Overloads Overrides Function GetInitializer(methodInfo As _
LogicalMethodInfo, _
attribute As SoapExtensionAttribute) As Object
Return CType(attribute, TraceExtensionAttribute).Filename
End Function
' The SOAP extension was configured to run using a configuration file
' instead of an attribute applied to a specific Web service
' method. Return a file name based on the class implementing the Web
' Service's type.
Public Overloads Overrides Function GetInitializer(WebServiceType As _
Type) As Object
' Return a file name to log the trace information to, based on the
' type.
Return "C:\" + WebServiceType.FullName + ".log"
End Function
' Receive the file name stored by GetInitializer and store it in a
' member variable for this specific instance.
Public Overrides Sub Initialize(initializer As Object)
m_filename= CStr(initializer)
End Sub
' If the SoapMessageStage is such that the SoapRequest or SoapResponse
' is still in the SOAP format to be sent or received over the network,
' save it out to file.
Public Overrides Sub ProcessMessage(message As SoapMessage)
Select Case message.Stage
Case SoapMessageStage.BeforeSerialize
Case SoapMessageStage.AfterSerialize
WriteOutput(message)
Case SoapMessageStage.BeforeDeserialize
WriteInput(message)
Case SoapMessageStage.AfterDeserialize
Case Else
Throw New Exception("invalid stage")
End Select
End Sub
' Write the SOAP message out to a file.
Public Sub WriteOutput(message As SoapMessage)
newStream.Position = 0
Dim fs As New FileStream(m_filename, FileMode.Append, _
FileAccess.Write)
Dim w As New StreamWriter(fs)
w.WriteLine("-----Response at " + DateTime.Now.ToString())
w.Flush()
Copy(newStream, fs)
w.Close()
newStream.Position = 0
Copy(newStream, oldStream)
End Sub
' Write the SOAP message out to a file.
Public Sub WriteInput(message As SoapMessage)
Copy(oldStream, newStream)
Dim fs As New FileStream(m_filename, FileMode.Append, _
FileAccess.Write)
Dim w As New StreamWriter(fs)
w.WriteLine("----- Request at " + DateTime.Now.ToString())
w.Flush()
newStream.Position = 0
Copy(newStream, fs)
w.Close()
newStream.Position = 0
End Sub
Sub Copy(fromStream As Stream, toStream As Stream)
Dim reader As New StreamReader(fromStream)
Dim writer As New StreamWriter(toStream)
writer.WriteLine(reader.ReadToEnd())
writer.Flush()
End Sub
End Class
' Create a SoapExtensionAttribute for our SOAP Extension that can be
' applied to a Web service method.
<AttributeUsage(AttributeTargets.Method)> _
Public Class TraceExtensionAttribute
Inherits SoapExtensionAttribute
Private m_filename As String = "c:\log.txt"
Private m_priority As Integer
Public Overrides ReadOnly Property ExtensionType() As Type
Get
Return GetType(TraceExtension)
End Get
End Property
Public Overrides Property Priority() As Integer
Get
Return m_priority
End Get
Set
m_priority = value
End Set
End Property
Public Property Filename() As String
Get
Return m_filename
End Get
Set
m_filename= value
End Set
End Property
End Class
using System;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.IO;
using System.Net;
// Define a SOAP Extension that traces the SOAP request and SOAP
// response for the Web service method the SOAP extension is
// applied to.
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 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";
}
// 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;
default:
throw new Exception("invalid stage");
}
}
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 a Web service method.
[AttributeUsage(AttributeTargets.Method)]
public class TraceExtensionAttribute : SoapExtensionAttribute {
private string filename = "c:\\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;
}
}
}
另請參閱
工作
參考
SoapExtension
SoapExtensionAttribute
SoapMessageStage
LogicalMethodInfo
概念
使用 SOAP 擴充功能修改 SOAP 訊息
XML Web Service 存留期分析
建置 XML Web Service 用戶端