ServicePoint 类

定义

命名空间:

System.Net

程序集:

System.Net.ServicePoint.dll

Source:

ServicePoint.cs

为 HTTP 连接提供连接管理。

public ref class ServicePoint

public class ServicePoint

type ServicePoint = class

Public Class ServicePoint

继承

Object

ServicePoint

示例

下面的代码示例创建一个连接到 URI www.contoso.com的 ServicePoint 对象。

// This example shows how to use the ServicePoint and ServicePointManager classes.
// The ServicePointManager class uses the ServicePoint class to manage connections
// to a remote host. The networking classes reuse service points for all 
// requests to a given URI. In fact, the same ServicePoint object 
// is used to issue requests to Internet resources identified by the same
// scheme identifier (for example,  HTTP) and host fragment (for example,  www.contoso.com).  
// This should improve your application performance. 
// Reusing service points in this way can help improve application performance.
#using <System.dll>

using namespace System;
using namespace System::Net;
using namespace System::Threading;
using namespace System::Text::RegularExpressions;
void ShowProperties( ServicePoint^ sp )
{
   Console::WriteLine( "Done calling FindServicePoint()..." );
   
   // Display the ServicePoint Internet resource address.
   Console::WriteLine( "Address = {0}", sp->Address );
   
   // Display the date and time that the ServicePoint was last 
   // connected to a host.
   Console::WriteLine( "IdleSince = {0}", sp->IdleSince );
   
   // Display the maximum length of time that the ServicePoint instance  
   // is allowed to maintain an idle connection to an Internet  
   // resource before it is recycled for use in another connection.
   Console::WriteLine( "MaxIdleTime = {0}", sp->MaxIdleTime );
   
   Console::WriteLine( "ConnectionName = {0}", sp->ConnectionName );
   
   // Display the maximum number of connections allowed on this 
   // ServicePoint instance.
   Console::WriteLine( "ConnectionLimit = {0}", sp->ConnectionLimit );
   
   // Display the number of connections associated with this 
   // ServicePoint instance.
   Console::WriteLine( "CurrentConnections = {0}", sp->CurrentConnections );
   
   if ( sp->Certificate == nullptr )
      Console::WriteLine( "Certificate = (null)" );
   else
      Console::WriteLine( "Certificate = {0}", sp->Certificate );

   if ( sp->ClientCertificate == nullptr )
      Console::WriteLine( "Client Certificate = (null)" );
   else
      Console::WriteLine( "Client Certificate = {0}", sp->ClientCertificate );

   Console::WriteLine( "ProtocolVersion = {0}", sp->ProtocolVersion->ToString() );
   Console::WriteLine( "SupportsPipelining = {0}", sp->SupportsPipelining );
   
   Console::WriteLine( "UseNagleAlgorithm = {0} ", sp->UseNagleAlgorithm.ToString() );
   Console::WriteLine( "Expect 100-continue = {0}", sp->Expect100Continue.ToString() );
   
}


void makeWebRequest( int hashCode, String^ Uri )
{
   HttpWebResponse^ res = nullptr;
   
   // Make sure that the idle time has elapsed, so that a new 
   // ServicePoint instance is created.
   Console::WriteLine( "Sleeping for 2 sec." );
   Thread::Sleep( 2000 );
   try
   {
      
      // Create a request to the passed URI.
      HttpWebRequest^ req = dynamic_cast<HttpWebRequest^>(WebRequest::Create( Uri ));
      Console::WriteLine( "\nConnecting to {0} ............", Uri );
      
      // Get the response object.
      res = dynamic_cast<HttpWebResponse^>(req->GetResponse());
      Console::WriteLine( "Connected.\n" );
      ServicePoint^ currentServicePoint = req->ServicePoint;
      
      // Display new service point properties.
      int currentHashCode = currentServicePoint->GetHashCode();
      Console::WriteLine( "New service point hashcode: {0}", currentHashCode );
      Console::WriteLine( "New service point max idle time: {0}", currentServicePoint->MaxIdleTime );
      Console::WriteLine( "New service point is idle since {0}", currentServicePoint->IdleSince );
      
      // Check that a new ServicePoint instance has been created.
      if ( hashCode == currentHashCode )
            Console::WriteLine( "Service point reused." );
      else
            Console::WriteLine( "A new service point created." );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Source : {0}", e->Source );
      Console::WriteLine( "Message : {0}", e->Message );
   }
   finally
   {
      if ( res != nullptr )
            res->Close();
   }

}


// Show the user how to use this program when wrong inputs are entered.
void showUsage()
{
   Console::WriteLine( "Enter the proxy name as follows:" );
   Console::WriteLine( "\tcs_servicepoint proxyName" );
}


int main()
{
   array<String^>^args = Environment::GetCommandLineArgs();
   int port = 80;
   
   // Define a regular expression to parse the user's input.
   // This is a security check. It allows only
   // alphanumeric input strings between 2 to 40 characters long.
   Regex^ rex = gcnew Regex( "^[a-zA-Z]\\w{1,39}$" );
   if ( args->Length < 2 )
   {
      showUsage();
      return  -1;
   }

   String^ proxy = args[ 1 ];
   if ( (rex->Match(proxy))->Success != true )
   {
      Console::WriteLine( "Input string format not allowed." );
      return  -1;
   }

   String^ proxyAdd = String::Format( "http://{0}:{1}", proxy, port );
   
   // Create a proxy object.  
   WebProxy^ DefaultProxy = gcnew WebProxy( proxyAdd,true );
   
   // Set the proxy that all HttpWebRequest instances use.
   WebRequest::DefaultWebProxy = DefaultProxy;
   
   // Get the base interface for proxy access for the 
   // WebRequest-based classes.
   IWebProxy^ Iproxy = WebRequest::DefaultWebProxy;

   
   // Set the maximum number of ServicePoint instances to 
   // maintain. If a ServicePoint instance for that host already 
   // exists when your application requests a connection to
   // an Internet resource, the ServicePointManager object
   // returns this existing ServicePoint instance. If none exists 
   // for that host, it creates a new ServicePoint instance.
   ServicePointManager::MaxServicePoints = 4;
   
   // Set the maximum idle time of a ServicePoint instance to 10 seconds.
   // After the idle time expires, the ServicePoint object is eligible for
   // garbage collection and cannot be used by the ServicePointManager.
   ServicePointManager::MaxServicePointIdleTime = 10000;
   
   ServicePointManager::UseNagleAlgorithm = true;
   ServicePointManager::Expect100Continue = true;
   ServicePointManager::CheckCertificateRevocationList = true;
   ServicePointManager::DefaultConnectionLimit = ServicePointManager::DefaultPersistentConnectionLimit;
   
   // Create the Uri object for the resource you want to access.
   Uri^ MS = gcnew Uri( "http://msdn.microsoft.com/" );
   
   // Use the FindServicePoint method to find an existing 
   // ServicePoint object or to create a new one.   
   ServicePoint^ servicePoint = ServicePointManager::FindServicePoint( MS, Iproxy );
   ShowProperties( servicePoint );
   int hashCode = servicePoint->GetHashCode();
   Console::WriteLine( "Service point hashcode: {0}", hashCode );
   
   // Make a request with the same scheme identifier and host fragment
   // used to create the previous ServicePoint object.
   makeWebRequest( hashCode, "http://msdn.microsoft.com/library/" );
}

// This example shows how to use the ServicePoint and ServicePointManager classes.
// The ServicePointManager class uses the ServicePoint class to manage connections
// to a remote host. The networking classes reuse service points for all
// requests to a given URI. In fact, the same ServicePoint object
// is used to issue requests to Internet resources identified by the same
// scheme identifier (for example,  HTTP) and host fragment (for example,  www.contoso.com).
// This should improve your application performance.
// Reusing service points in this way can help improve application performance.
using System;
using System.Net;
using System.Threading;
using System.Text.RegularExpressions;

namespace Mssc.Services.ConnectionManagement
{
    class TestServicePoint
    {
        private static void ShowProperties(ServicePoint sp)
        {
            Console.WriteLine("Done calling FindServicePoint()...");

            // Display the ServicePoint Internet resource address.
            Console.WriteLine("Address = {0} ", sp.Address.ToString());

            // Display the date and time that the ServicePoint was last
            // connected to a host.
            Console.WriteLine("IdleSince = " + sp.IdleSince.ToString());

            // Display the maximum length of time that the ServicePoint instance
            // is allowed to maintain an idle connection to an Internet
            // resource before it is recycled for use in another connection.
            Console.WriteLine("MaxIdleTime = " + sp.MaxIdleTime);

            Console.WriteLine("ConnectionName = " + sp.ConnectionName);

            // Display the maximum number of connections allowed on this
            // ServicePoint instance.
            Console.WriteLine("ConnectionLimit = " + sp.ConnectionLimit);

            // Display the number of connections associated with this
            // ServicePoint instance.
            Console.WriteLine("CurrentConnections = " + sp.CurrentConnections);

            if (sp.Certificate == null)
                Console.WriteLine("Certificate = (null)");
            else
                Console.WriteLine("Certificate = " + sp.Certificate.ToString());

            if (sp.ClientCertificate == null)
                Console.WriteLine("ClientCertificate = (null)");
            else
                Console. WriteLine("ClientCertificate = " + sp.ClientCertificate.ToString());

            Console.WriteLine("ProtocolVersion = " + sp.ProtocolVersion.ToString());
            Console.WriteLine("SupportsPipelining = " + sp.SupportsPipelining);

            Console.WriteLine("UseNagleAlgorithm = " + sp.UseNagleAlgorithm.ToString());
            Console.WriteLine("Expect 100-continue = " + sp.Expect100Continue.ToString());
        }

        private static void makeWebRequest(int hashCode, string Uri)
        {
            HttpWebResponse res = null;

            // Make sure that the idle time has elapsed, so that a new
            // ServicePoint instance is created.
            Console.WriteLine("Sleeping for 2 sec.");
            Thread.Sleep(2000);
            try
            {
                // Create a request to the passed URI.
                HttpWebRequest req = (HttpWebRequest)WebRequest.Create(Uri);

                Console.WriteLine("\nConnecting to " + Uri + " ............");

                // Get the response object.
                res = (HttpWebResponse)req.GetResponse();
                Console.WriteLine("Connected.\n");

                ServicePoint currentServicePoint = req.ServicePoint;

                // Display new service point properties.
                int currentHashCode = currentServicePoint.GetHashCode();

                Console.WriteLine("New service point hashcode: " + currentHashCode);
                Console.WriteLine("New service point max idle time: " + currentServicePoint.MaxIdleTime);
                Console.WriteLine("New service point is idle since " + currentServicePoint.IdleSince );

                // Check that a new ServicePoint instance has been created.
                if (hashCode == currentHashCode)
                    Console.WriteLine("Service point reused.");
                else
                    Console.WriteLine("A new service point created.") ;
            }
            catch (Exception e)
            {
                Console.WriteLine("Source : " + e.Source);
                Console.WriteLine("Message : " + e.Message);
            }
            finally
            {
                if (res != null)
                    res.Close();
            }
        }

        // Show the user how to use this program when wrong inputs are entered.
        private static void showUsage()
        {
            Console.WriteLine("Enter the proxy name as follows:");
            Console.WriteLine("\tcs_servicepoint proxyName");
        }

        public static void Main(string[] args)
        {
            int port = 80;

            // Define a regular expression to parse the user's input.
            // This is a security check. It allows only
            // alphanumeric input strings between 2 to 40 characters long.
            Regex rex = new Regex(@"^[a-zA-Z]\w{1,39}$");

            if (args.Length < 1)
            {
                showUsage();
                return;
            }
            string proxy = args[0];

            if ((rex.Match(proxy)).Success != true)
            {
                Console.WriteLine("Input string format not allowed.");
                return;
            }
            string proxyAdd = "http://" + proxy + ":" + port;

            // Create a proxy object.
            WebProxy DefaultProxy = new WebProxy(proxyAdd, true);

            // Set the proxy that all HttpWebRequest instances use.
            WebRequest.DefaultWebProxy = DefaultProxy;

            // Get the base interface for proxy access for the
            // WebRequest-based classes.
            IWebProxy Iproxy = WebRequest.DefaultWebProxy;

            // Set the maximum number of ServicePoint instances to
            // maintain. If a ServicePoint instance for that host already
            // exists when your application requests a connection to
            // an Internet resource, the ServicePointManager object
            // returns this existing ServicePoint instance. If none exists
            // for that host, it creates a new ServicePoint instance.
            ServicePointManager.MaxServicePoints = 4;

            // Set the maximum idle time of a ServicePoint instance to 10 seconds.
            // After the idle time expires, the ServicePoint object is eligible for
            // garbage collection and cannot be used by the ServicePointManager object.
            ServicePointManager.MaxServicePointIdleTime = 10000;

            ServicePointManager.UseNagleAlgorithm = true;
            ServicePointManager.Expect100Continue = true;
            ServicePointManager.CheckCertificateRevocationList = true;
            ServicePointManager.DefaultConnectionLimit = ServicePointManager.DefaultPersistentConnectionLimit;
            // Create the Uri object for the resource you want to access.
            Uri MS = new Uri("http://msdn.microsoft.com/");

            // Use the FindServicePoint method to find an existing
            // ServicePoint object or to create a new one.
            ServicePoint servicePoint = ServicePointManager.FindServicePoint(MS, Iproxy);

            ShowProperties(servicePoint);

            int hashCode = servicePoint.GetHashCode();

            Console.WriteLine("Service point hashcode: " + hashCode);

            // Make a request with the same scheme identifier and host fragment
            // used to create the previous ServicePoint object.
            makeWebRequest(hashCode, "http://msdn.microsoft.com/library/");
        }
    }
}

' This example shows how to use the ServicePoint and ServicePointManager classes.
' The ServicePointManager class uses the ServicePoint class to manage connections
' to a remote host. The networking classes reuse service points for all 
' requests to a given URI. In fact, the same ServicePoint object 
' is used to issue requests to Internet resources identified by the same
' scheme identifier (for example,  HTTP) and host fragment (for example,  www.contoso.com).  
' Reusing service points in this way can help improve application  performance.

Imports System.Net
Imports System.Threading
Imports System.Text.RegularExpressions

Namespace Mssc.Services.ConnectionManagement
    Module M_TestServicePoint

        Class TestServicePoint
            Private Shared Sub ShowProperties(ByVal sp As ServicePoint)

                Console.WriteLine("Done calling FindServicePoint")

                ' Display the ServicePoint Internet resource address.
                Console.WriteLine(("Address = " + sp.Address.ToString()))

                ' Display the date and time that the ServicePoint was last 
                ' connected to a host.
                Console.WriteLine(("IdleSince = " + sp.IdleSince.ToString()))


                ' Display the maximum length of time that the ServicePoint instance 
                ' is allowed to maintain an idle connection to an Internet  
                ' resource before it is recycled for use in another connection.
                Console.WriteLine(("MaxIdleTime = " + sp.MaxIdleTime.ToString()))

                Console.WriteLine(("ConnectionName = " + sp.ConnectionName))

                ' Display the maximum number of connections allowed on this 
                ' ServicePoint instance.
                Console.WriteLine(("ConnectionLimit = " + sp.ConnectionLimit.ToString()))

                ' Display the number of connections associated with this 
                ' ServicePoint instance.
                Console.WriteLine(("CurrentConnections = " + sp.CurrentConnections.ToString()))

                If sp.Certificate Is Nothing Then
                    Console.WriteLine("Certificate = (null)")
                Else
                    Console.WriteLine(("Certificate = " + sp.Certificate.ToString()))
                End If

                If sp.ClientCertificate Is Nothing Then
                    Console.WriteLine("ClientCertificate = (null)")
                Else
                    Console.WriteLine(("ClientCertificate = " + sp.ClientCertificate.ToString()))
                End If

                Console.WriteLine("ProtocolVersion = " + sp.ProtocolVersion.ToString())
                Console.WriteLine(("SupportsPipelining = " + sp.SupportsPipelining.ToString()))


                Console.WriteLine("UseNagleAlgorithm = " + sp.UseNagleAlgorithm.ToString())
                Console.WriteLine("Expect 100-continue = " + sp.Expect100Continue.ToString())
            End Sub





            Private Shared Sub makeWebRequest(ByVal hashCode As Integer, ByVal Uri As String)
                Dim res As HttpWebResponse = Nothing

                ' Make sure that the idle time has elapsed, so that a new 
                ' ServicePoint instance is created.
                Console.WriteLine("Sleeping for 2 sec.")
                Thread.Sleep(2000)

                Try
                    ' Create a request to the passed URI.
                    Dim req As HttpWebRequest = CType(WebRequest.Create(Uri), HttpWebRequest)
                    Console.WriteLine((ControlChars.Lf + "Connecting to " + Uri + " ............"))

                    ' Get the response object.
                    res = CType(req.GetResponse(), HttpWebResponse)
                    Console.WriteLine("Connected." + ControlChars.Lf)
                    Dim currentServicePoint As ServicePoint = req.ServicePoint

                    ' Display new service point properties.
                    Dim currentHashCode As Integer = currentServicePoint.GetHashCode()
                    Console.WriteLine(("New service point hashcode: " + currentHashCode.ToString()))
                    Console.WriteLine(("New service point max idle time: " + currentServicePoint.MaxIdleTime.ToString()))
                    Console.WriteLine(("New service point is idle since " + currentServicePoint.IdleSince.ToString()))

                    ' Check that a new ServicePoint instance has been created.
                    If hashCode = currentHashCode Then
                        Console.WriteLine("Service point reused.")
                    Else
                        Console.WriteLine("A new service point created.")
                    End If
                Catch e As Exception
                    Console.WriteLine(("Source : " + e.Source))
                    Console.WriteLine(("Message : " + e.Message))
                Finally
                    If Not (res Is Nothing) Then
                        res.Close()
                    End If
                End Try
            End Sub


            ' Show the user how to use this program when wrong inputs are entered.
            Private Shared Sub showUsage()
                Console.WriteLine("Enter the proxy name as follows:")
                Console.WriteLine(ControlChars.Tab + "vb_servicepoint proxyName")
            End Sub

            ' This is the program entry point. It allows the user to enter 
            ' a server name that is used to locate its current homepage.
            Public Shared Sub Main(ByVal args() As String)
                Dim proxy As String = Nothing
                Dim port As Integer = 80

                ' Define a regular expression to parse the user's input.
                ' This is a security check. It allows only
                ' alphanumeric input strings between 2 to 40 characters long.
                Dim rex As New Regex("^[a-zA-Z]\w{1,39}$")

                If args.Length = 0 Then
                    ' Show how to use this program.
                    showUsage()
                    Return
                End If

                proxy = args(0)
                If (Not (rex.Match(proxy)).Success) Then
                    Console.WriteLine("Input string format not allowed.")
                    Return
                End If

                ' Create a proxy object.  
                Dim proxyAdd As String
                proxyAdd = "http://" + proxy + ":" + port.ToString()


                Dim DefaultProxy As New WebProxy(proxyAdd, True)

                ' Set the proxy that all HttpWebRequest instances use.
                WebRequest.DefaultWebProxy = DefaultProxy


                ' Get the base interface for proxy access for the 
                ' WebRequest-based classes.
                Dim Iproxy As IWebProxy = WebRequest.DefaultWebProxy

                ' Set the maximum number of ServicePoint instances to maintain.
                ' Note that, if a ServicePoint instance for that host already 
                ' exists when your application requests a connection to
                ' an Internet resource, the ServicePointManager object
                ' returns this existing ServicePoint. If none exists 
                ' for that host, it creates a new ServicePoint instance.
                ServicePointManager.MaxServicePoints = 4

                ' Set the maximum idle time of a ServicePoint instance to 10 seconds.
                ' After the idle time expires, the ServicePoint object is eligible for
                ' garbage collection and cannot be used by the ServicePointManager.
                ServicePointManager.MaxServicePointIdleTime = 10000


                ServicePointManager.UseNagleAlgorithm = True
                ServicePointManager.Expect100Continue = True
                ServicePointManager.CheckCertificateRevocationList = True
                ServicePointManager.DefaultConnectionLimit = _
                    ServicePointManager.DefaultPersistentConnectionLimit
                ' Create the Uri object for the resource you want to access.
                Dim MS As New Uri("http://msdn.microsoft.com/")

                ' Use the FindServicePoint method to find an existing 
                ' ServicePoint object or to create a new one.   
                Dim servicePoint As ServicePoint = ServicePointManager.FindServicePoint(MS, Iproxy)
                ShowProperties(servicePoint)
                Dim hashCode As Integer = servicePoint.GetHashCode()
                Console.WriteLine(("Service point hashcode: " + hashCode.ToString()))

                ' Make a request with the same scheme identifier and host fragment
                ' used to create the previous ServicePoint object.
                makeWebRequest(hashCode, "http://msdn.microsoft.com/library/")

            End Sub


        End Class

    End Module
End Namespace

注解

谨慎

WebRequest、HttpWebRequest、ServicePoint和 WebClient 已过时，不应将其用于新开发。 请改用 HttpClient。

ServicePoint 类基于在资源的统一资源标识符（URI）中传递的主机信息处理与 Internet 资源的连接。 与资源的初始连接确定 ServicePoint 对象维护的信息，然后由该资源的所有后续请求共享。

ServicePoint 对象由 ServicePointManager 类管理，并在必要时由 ServicePointManager.FindServicePoint 方法创建。 ServicePoint 对象永远不会直接创建，但始终由 ServicePointManager 类创建和管理。 ServicePointManager.MaxServicePoints 属性设置可以创建的最大 ServicePoint 对象数。

每个 ServicePoint 对象保持其与 Internet 资源的连接，直到其空闲时间超过 MaxIdleTime 属性中指定的时间。 当 ServicePoint 超过 MaxIdleTime 值时，可以将其回收到另一个连接。 MaxIdleTime 的默认值由 ServicePointManager.MaxServicePointIdleTime 属性设置。

当 ConnectionLeaseTimeout 属性设置为非 -1 的值，并在指定的时间过后关闭活动 ServicePoint 连接后，它将在服务下一个请求后关闭。 这对于不需要无限期打开的活动连接的应用程序非常有用，因为它们在默认情况下处于默认状态。

注意

在高负载条件下，某些应用程序可能会耗尽 ThreadPool 中的可用线程，这可能会导致系统性能不佳（如高事务时间和可变事务时间）。

属性

Address	获取此 ServicePoint 对象连接到的服务器统一资源标识符（URI）。
BindIPEndPointDelegate	指定要将本地 IPEndPoint 与 ServicePoint关联的委托。
Certificate	获取为此 ServicePoint 对象收到的证书。
ClientCertificate	获取发送到服务器的最后一个客户端证书。
ConnectionLeaseTimeout	获取或设置活动 ServicePoint 连接关闭后的毫秒数。
ConnectionLimit	获取或设置此 ServicePoint 对象上允许的最大连接数。
ConnectionName	获取连接名称。
CurrentConnections	获取与此 ServicePoint 对象关联的打开连接数。
Expect100Continue	获取或设置一个 Boolean 值，该值确定是否使用 100-Continue 行为。
IdleSince	获取 ServicePoint 对象上次连接到主机的日期和时间。
MaxIdleTime	获取或设置与 ServicePoint 对象关联的连接在连接关闭之前可以保持空闲的时间量。
ProtocolVersion	获取 ServicePoint 对象使用的 HTTP 协议的版本。
ReceiveBufferSize	获取或设置此 ServicePoint使用的套接字的接收缓冲区的大小。
SupportsPipelining	指示 ServicePoint 对象是否支持管道连接。
UseNagleAlgorithm	获取或设置一个 Boolean 值，该值确定是否在此 ServicePoint 对象管理的连接上使用 Nagle 算法。

方法

CloseConnectionGroup(String)	从此 ServicePoint 对象中删除指定的连接组。
Equals(Object)	确定指定的对象是否等于当前对象。 (继承自 Object)
GetHashCode()	用作默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object的浅表副本。 (继承自 Object)
SetTcpKeepAlive(Boolean, Int32, Int32)	启用或禁用 TCP 连接的保持活动选项。
ToString()	返回一个表示当前对象的字符串。 (继承自 Object)