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ServicePoint, classe

Mise à jour : novembre 2007

Assure la gestion des connexions HTTP.

Espace de noms :  System.Net
Assembly :  System (dans System.dll)

public class ServicePoint
public class ServicePoint
public class ServicePoint

La classe ServicePoint gère les connexions à une ressource Internet en fonction des informations d'hôte passées dans l'URI (Uniform Resource Identifier) de la ressource. La connexion initiale à la ressource détermine les informations gérées par l'objet ServicePoint, qui sont ensuite partagées par toutes les demandes suivantes adressées à cette ressource.

Les objets ServicePoint sont gérés par la classe ServicePointManager et sont créés, si nécessaire, par la méthode ServicePointManager.FindServicePoint. Les objets ServicePoint ne sont jamais créés directement ; ils sont toujours créés et gérés par la classe ServicePointManager. Le nombre maximal d'objets ServicePoint qui peuvent être créés est défini par la propriété ServicePointManager.MaxServicePoints.

Chaque objet ServicePoint gère sa connexion à la ressource Internet jusqu'à ce qu'il ait été inactif pendant une durée supérieure à celle spécifiée dans la propriété MaxIdleTime. Lorsque ServicePoint dépasse la valeur de MaxIdleTime, il peut être recyclé dans une autre connexion. La valeur par défaut de MaxIdleTime est définie par la propriété ServicePointManager.MaxServicePointIdleTime.

Si la propriété ConnectionLeaseTimeout a une valeur autre que -1 et une fois le temps spécifié écoulé, une connexion ServicePoint active est fermée lorsqu'elle a fourni la demande suivante. Cela peut être utile pour les applications qui n'exigent pas des connexions actives ouvertes indéfiniment, comme elles le sont par défaut.

Remarque :

Dans des conditions de charge élevée, certaines applications peuvent ne plus disposer de suffisamment de threads libres dans ThreadPool, ce qui peut provoquer la dégradation des performances système (notamment des temps de transaction élevés et variables). Consultez http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag/html/scalenetchapt17.asp pour obtenir une liste de modifications de configuration que vous pouvez apporter pour résoudre ce problème.

L'exemple de code suivant crée un objet ServicePoint qui se connecte à l'URI www.contoso.com.

// 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/");



        }

    }
}


package Mssc.Services.ConnectionManagement ; 
// 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.
import System.*;
import System.Net.*;
import System.Threading.*;
import System.Text.RegularExpressions.*;

class TestServicePoint
{
    private static void ShowProperties(ServicePoint sp)
    {
        Console.WriteLine("Done calling FindServicePoint()...");
        // Display the ServicePoint Internet resource address.
        Console.WriteLine("Address = {0} ", sp.get_Address().ToString());

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

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

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

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

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

        if (sp.get_ClientCertificate() == null) {
            Console.WriteLine("ClientCertificate = (null)");
        }
        else {
            Console.WriteLine(("ClientCertificate = " 
                + sp.get_ClientCertificate().ToString()));
        }
        Console.WriteLine(("ProtocolVersion = " 
            + sp.get_ProtocolVersion().ToString()));
        Console.WriteLine(("SupportsPipelining = " 
            + sp.get_SupportsPipelining()));

        Console.WriteLine(("UseNagleAlgorithm = " 
            + System.Convert.ToString(sp.get_UseNagleAlgorithm())));
        Console.WriteLine(("Expect 100-continue = " 
            + System.Convert.ToString(sp.get_Expect100Continue())));
    } //ShowProperties

    private static void MakeWebRequest(int hashCode, String uri) 
        throws InterruptedException
    {
        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.get_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.get_MaxIdleTime()));
            Console.WriteLine(("New service point is idle since " 
                + currentServicePoint.get_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 (System.Exception e) {
            Console.WriteLine(("Source : " + e.get_Source()));
            Console.WriteLine(("Message : " + e.get_Message()));
        }
        finally {
            if ( res  != null  ) {
               res.Close();
            }
         }
    } //MakeWebRequest

    // 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");
    } //ShowUsage

    public static void main(String[] args) throws InterruptedException
    {
        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).get_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.set_DefaultWebProxy(DefaultProxy);

        // Get the base interface for proxy access for the 
        // WebRequest-based classes.
        IWebProxy Iproxy = WebRequest.get_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.set_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.set_MaxServicePointIdleTime(10000);

        ServicePointManager.set_UseNagleAlgorithm(true);
        ServicePointManager.set_Expect100Continue(true);
        ServicePointManager.set_CheckCertificateRevocationList(true);
        ServicePointManager.set_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/");
    } //main 
} //TestServicePoint


System.Object
  System.Net.ServicePoint

Tous les membres static (Shared en Visual Basic) publics de ce type sont thread-safe. Il n'est pas garanti que les membres d'instance soient thread-safe.

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professionnel Édition x64, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile pour Smartphone, Windows Mobile pour Pocket PC

Le .NET Framework et le .NET Compact Framework ne prennent pas en charge toutes les versions de chaque plateforme. Pour obtenir la liste des versions prises en charge, consultez Configuration requise du .NET Framework.

.NET Framework

Pris en charge dans : 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Pris en charge dans : 3.5, 2.0, 1.0
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