WebClient_2_1.cs :  » 2.6.4-mono-.net-core » System.Net » System » Net » C# / CSharp Open Source

Home
C# / CSharp Open Source
1.2.6.4 mono .net core
2.2.6.4 mono core
3.Aspect Oriented Frameworks
4.Bloggers
5.Build Systems
6.Business Application
7.Charting Reporting Tools
8.Chat Servers
9.Code Coverage Tools
10.Content Management Systems CMS
11.CRM ERP
12.Database
13.Development
14.Email
15.Forum
16.Game
17.GIS
18.GUI
19.IDEs
20.Installers Generators
21.Inversion of Control Dependency Injection
22.Issue Tracking
23.Logging Tools
24.Message
25.Mobile
26.Network Clients
27.Network Servers
28.Office
29.PDF
30.Persistence Frameworks
31.Portals
32.Profilers
33.Project Management
34.RSS RDF
35.Rule Engines
36.Script
37.Search Engines
38.Sound Audio
39.Source Control
40.SQL Clients
41.Template Engines
42.Testing
43.UML
44.Web Frameworks
45.Web Service
46.Web Testing
47.Wiki Engines
48.Windows Presentation Foundation
49.Workflows
50.XML Parsers
C# / C Sharp
C# / C Sharp by API
C# / CSharp Tutorial
C# / CSharp Open Source » 2.6.4 mono .net core » System.Net 
System.Net » System » Net » WebClient_2_1.cs
//
// System.Net.WebClient
//
// Authors:
//   Lawrence Pit (loz@cable.a2000.nl)
//  Gonzalo Paniagua Javier (gonzalo@ximian.com)
//  Atsushi Enomoto (atsushi@ximian.com)
//  Miguel de Icaza (miguel@ximian.com)
//  Stephane Delcroix (sdelcroix@novell.com)
//
// Copyright 2003 Ximian, Inc. (http://www.ximian.com)
// Copyright 2006, 2008, 2009-2010 Novell, Inc. (http://www.novell.com)
//
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System.IO;
using System.Text;
using System.Threading;

namespace System.Net{

  // note: this type is effectively sealed to transparent code since it's default .ctor is marked with [SecuritySafeCritical]
  public class WebClient {

    WebHeaderCollection headers;
    WebHeaderCollection responseHeaders;
    string baseAddress;
    bool is_busy;
    Encoding encoding = Encoding.UTF8;
    bool allow_read_buffering = true;
    bool allow_write_buffering = true;
    WebRequest request;
    object locker;
    CallbackData callback_data;

    public WebClient ()
    {
      // kind of calling NativeMethods.plugin_instance_get_source_location (PluginHost.Handle)
      // but without adding dependency on System.Windows.dll. GetData is [SecurityCritical]
      // this makes the default .ctor [SecuritySafeCritical] which would be a problem (inheritance)
      // but it happens that MS SL2 also has this default .ctor as SSC :-)
      baseAddress = (AppDomain.CurrentDomain.GetData ("xap_uri") as string);
      locker = new object ();
      UseDefaultCredentials = true;
    }
    
    // Properties
    
    public string BaseAddress {
      get { return baseAddress; }
      set {
        if (String.IsNullOrEmpty (value)) {
          baseAddress = String.Empty;
        } else {
          Uri uri = null;
          if (!Uri.TryCreate (value, UriKind.Absolute, out uri))
            throw new ArgumentException ("Invalid URI");

          baseAddress = Uri.UnescapeDataString (uri.AbsoluteUri);
        }
      }
    }

    [MonoTODO ("provide credentials to the client stack")]
    public ICredentials Credentials { get; set; }

    // this is an unvalidated collection, HttpWebRequest is responsable to validate it
    public WebHeaderCollection Headers {
      get {
        if (headers == null)
          headers = new WebHeaderCollection ();

        return headers;
      }
      set { headers = value; }
    }

    public WebHeaderCollection ResponseHeaders {
      get { return responseHeaders; }
    }

    public Encoding Encoding {
      get { return encoding; }
      set {
        if (value == null)
          throw new ArgumentNullException ("value");
        encoding = value;
      }
    }

    public bool IsBusy {
      get { return is_busy; }
    }

    [MonoTODO ("value is unused, current implementation always works like it's true (default)")]
    public bool AllowReadStreamBuffering {
      get { return allow_read_buffering; }
      set { allow_read_buffering = value; }
    }

    // new in SL4 RC
    [MonoTODO ("value is unused, current implementation always works like it's true (default)")]
    public bool AllowWriteStreamBuffering {
      get { return allow_write_buffering; }
      set { allow_write_buffering = value; }
    }

    public bool UseDefaultCredentials {
      get; set;
    }

    // Methods

    void CheckBusy ()
    {
      if (IsBusy)
        throw new NotSupportedException ("WebClient does not support conccurent I/O operations.");
    }

    void SetBusy ()
    {
      lock (locker) {
        CheckBusy ();
        is_busy = true;
      }
    }

    private string DetermineMethod (Uri address, string method)
    {
      if (method != null)
        return method;

      if (address.Scheme == Uri.UriSchemeFtp)
        return "RETR";
      return "POST";
    }

    public event DownloadProgressChangedEventHandler DownloadProgressChanged;
    public event DownloadStringCompletedEventHandler DownloadStringCompleted;
    public event OpenReadCompletedEventHandler OpenReadCompleted;
    public event OpenWriteCompletedEventHandler OpenWriteCompleted;
    public event UploadProgressChangedEventHandler UploadProgressChanged;
    public event UploadStringCompletedEventHandler UploadStringCompleted;
    public event WriteStreamClosedEventHandler WriteStreamClosed;

    WebRequest SetupRequest (Uri uri, string method, CallbackData callbackData)
    {
      callback_data = callbackData;
      WebRequest request = GetWebRequest (uri);
      request.Method = DetermineMethod (uri, method);
      foreach (string header in Headers.AllKeys)
        request.Headers.SetHeader (header, Headers [header]);
      return request;
    }

    Stream ProcessResponse (WebResponse response)
    {
      responseHeaders = response.Headers;
      HttpWebResponse hwr = (response as HttpWebResponse);
      if (hwr == null)
        throw new NotSupportedException ();

      HttpStatusCode status_code = HttpStatusCode.NotFound;
      Stream s = null;
      try {
        status_code = hwr.StatusCode;
        if (status_code == HttpStatusCode.OK)
          s = response.GetResponseStream ();
      }
      catch (Exception e) {
        throw new WebException ("NotFound", e, WebExceptionStatus.UnknownError, response);
      }
      finally {
        if (status_code != HttpStatusCode.OK)
          throw new WebException ("NotFound", null, WebExceptionStatus.UnknownError, response);
      }
      return s;
    }

    public void CancelAsync ()
    {
      if (request != null)
        request.Abort ();
    }

    void CompleteAsync ()
    {
      is_busy = false;
    }

    class CallbackData {
      public object user_token;
      public SynchronizationContext sync_context;
      public byte [] data;
      public CallbackData (object user_token, byte [] data)
      {
        this.user_token = user_token;
        this.data = data;
        this.sync_context = SynchronizationContext.Current ?? new SynchronizationContext ();
      }
      public CallbackData (object user_token) : this (user_token, null)
      {
      }
    }

    //    DownloadStringAsync

    public void DownloadStringAsync (Uri address)
    {
      DownloadStringAsync (address, null);
    }

    public void DownloadStringAsync (Uri address, object userToken)
    {
      if (address == null)
        throw new ArgumentNullException ("address");

      lock (locker) {
        SetBusy ();

        try {
          request = SetupRequest (address, "GET", new CallbackData (userToken));
          request.BeginGetResponse (new AsyncCallback (DownloadStringAsyncCallback), null);
        }
        catch (Exception e) {
          WebException wex = new WebException ("Could not start operation.", e);
          OnDownloadStringCompleted (
            new DownloadStringCompletedEventArgs (null, wex, false, userToken));
        }
      }
    }

    private void DownloadStringAsyncCallback (IAsyncResult result)
    {
      string data = null;
      Exception ex = null;
      bool cancel = false;
      try {
        WebResponse response = request.EndGetResponse (result);
        Stream stream = ProcessResponse (response);

        using (StreamReader sr = new StreamReader (stream, encoding, true)) {
          data = sr.ReadToEnd ();
        }
      }
      catch (WebException web) {
        cancel = (web.Status == WebExceptionStatus.RequestCanceled);
        ex = web;
      }
      catch (Exception e) {
        ex = e;
      }
      finally {
        callback_data.sync_context.Post (delegate (object sender) {
          OnDownloadStringCompleted (new DownloadStringCompletedEventArgs (data, ex, cancel, callback_data.user_token));
        }, null);
      }
    }

    //    OpenReadAsync

    public void OpenReadAsync (Uri address)
    {
      OpenReadAsync (address, null);
    }

    public void OpenReadAsync (Uri address, object userToken)
    {
      if (address == null)
        throw new ArgumentNullException ("address");

      lock (locker) {
        SetBusy ();

        try {
          request = SetupRequest (address, "GET", new CallbackData (userToken));
          request.BeginGetResponse (new AsyncCallback (OpenReadAsyncCallback), null);
        }
        catch (Exception e) {
          WebException wex = new WebException ("Could not start operation.", e);
          OnOpenReadCompleted (
            new OpenReadCompletedEventArgs (null, wex, false, userToken));
        }
      }
    }

    private void OpenReadAsyncCallback (IAsyncResult result)
    {
      Stream stream = null;
      Exception ex = null;
      bool cancel = false;
      try {
        WebResponse response = request.EndGetResponse (result);
        stream = ProcessResponse (response);
      }
      catch (WebException web) {
        cancel = (web.Status == WebExceptionStatus.RequestCanceled);
        ex = web;
      }
      catch (Exception e) {
        ex = e;
      }
      finally {
        callback_data.sync_context.Post (delegate (object sender) {
          OnOpenReadCompleted (new OpenReadCompletedEventArgs (stream, ex, cancel, callback_data.user_token));
        }, null);
      }
    }

    //    OpenWriteAsync

    public void OpenWriteAsync (Uri address)
    {
      OpenWriteAsync (address, null);
    }

    public void OpenWriteAsync (Uri address, string method)
    {
      OpenWriteAsync (address, method, null);
    }

    public void OpenWriteAsync (Uri address, string method, object userToken)
    {
      if (address == null)
        throw new ArgumentNullException ("address");

      lock (locker) {
        SetBusy ();

        try {
          request = SetupRequest (address, method, new CallbackData (userToken));
          request.BeginGetRequestStream (new AsyncCallback (OpenWriteAsyncCallback), null);
        }
        catch (Exception e) {
          WebException wex = new WebException ("Could not start operation.", e);
          OnOpenWriteCompleted (
            new OpenWriteCompletedEventArgs (null, wex, false, userToken));
        }
      }
    }

    private void OpenWriteAsyncCallback (IAsyncResult result)
    {
      Stream stream = null;
      Exception ex = null;
      bool cancel = false;
      InternalWebRequestStreamWrapper internal_stream;

      try {
        stream = request.EndGetRequestStream (result);
        internal_stream = (InternalWebRequestStreamWrapper) stream;
        internal_stream.WebClient = this;
        internal_stream.WebClientData = callback_data;
      }
      catch (WebException web) {
        cancel = (web.Status == WebExceptionStatus.RequestCanceled);
        ex = web;
      }
      catch (Exception e) {
        ex = e;
      }
      finally {
        callback_data.sync_context.Post (delegate (object sender) {
          OnOpenWriteCompleted (new OpenWriteCompletedEventArgs (stream, ex, cancel, callback_data.user_token));
        }, null);
      }
    }

    internal void WriteStreamClosedCallback (object WebClientData)
    {
      try {
        request.BeginGetResponse (OpenWriteAsyncResponseCallback, WebClientData);
      }
      catch (Exception e) {
        callback_data.sync_context.Post (delegate (object sender) {
          OnWriteStreamClosed (new WriteStreamClosedEventArgs (e));
        }, null);
      }
    }

    private void OpenWriteAsyncResponseCallback (IAsyncResult result)
    {
      try {
        WebResponse response = request.EndGetResponse (result);
        ProcessResponse (response);
      }
      catch (Exception e) {
        callback_data.sync_context.Post (delegate (object sender) {
          OnWriteStreamClosed (new WriteStreamClosedEventArgs (e));
        }, null);
      }
    }

    //    UploadStringAsync

    public void UploadStringAsync (Uri address, string data)
    {
      UploadStringAsync (address, null, data);
    }

    public void UploadStringAsync (Uri address, string method, string data)
    {
      UploadStringAsync (address, method, data, null);
    }

    public void UploadStringAsync (Uri address, string method, string data, object userToken)
    {
      if (address == null)
        throw new ArgumentNullException ("address");
      if (data == null)
        throw new ArgumentNullException ("data");

      lock (locker) {
        SetBusy ();

        try {
          request = SetupRequest (address, method, new CallbackData (userToken, encoding.GetBytes (data)));
          request.BeginGetRequestStream (new AsyncCallback (UploadStringRequestAsyncCallback), null);
        }
        catch (Exception e) {
          WebException wex = new WebException ("Could not start operation.", e);
          OnUploadStringCompleted (
            new UploadStringCompletedEventArgs (null, wex, false, userToken));
        }
      }
    }

    private void UploadStringRequestAsyncCallback (IAsyncResult result)
    {
      try {
        Stream stream = request.EndGetRequestStream (result);
        stream.Write (callback_data.data, 0, callback_data.data.Length);
        request.BeginGetResponse (new AsyncCallback (UploadStringResponseAsyncCallback), null);
      }
      catch {
        request.Abort ();
        throw;
      }
    }

    private void UploadStringResponseAsyncCallback (IAsyncResult result)
    {
      string data = null;
      Exception ex = null;
      bool cancel = false;
      try {
        WebResponse response = request.EndGetResponse (result);
        Stream stream = ProcessResponse (response);

        using (StreamReader sr = new StreamReader (stream, encoding, true)) {
          data = sr.ReadToEnd ();
        }
      }
      catch (WebException web) {
        cancel = (web.Status == WebExceptionStatus.RequestCanceled);
        ex = web;
      }
      catch (InvalidOperationException ioe) {
        ex = new WebException ("An exception occurred during a WebClient request", ioe);
      }
      catch (Exception e) {
        ex = e;
      }
      finally {
        callback_data.sync_context.Post (delegate (object sender) {
          OnUploadStringCompleted (new UploadStringCompletedEventArgs (data, ex, cancel, callback_data.user_token));
        }, null);
      }
    }

    protected virtual void OnDownloadProgressChanged (DownloadProgressChangedEventArgs e)
    {
      DownloadProgressChangedEventHandler handler = DownloadProgressChanged;
      if (handler != null)
        handler (this, e);
    }
    
    protected virtual void OnOpenReadCompleted (OpenReadCompletedEventArgs args)
    {
      CompleteAsync ();
      OpenReadCompletedEventHandler handler = OpenReadCompleted;
      if (handler != null)
        handler (this, args);
    }

    protected virtual void OnDownloadStringCompleted (DownloadStringCompletedEventArgs args)
    {
      CompleteAsync ();
      DownloadStringCompletedEventHandler handler = DownloadStringCompleted;
      if (handler != null)
        handler (this, args);
    }

    protected virtual void OnOpenWriteCompleted (OpenWriteCompletedEventArgs args)
    {
      CompleteAsync ();
      OpenWriteCompletedEventHandler handler = OpenWriteCompleted;
      if (handler != null)
        handler (this, args);
    }

    protected virtual void OnUploadProgressChanged (UploadProgressChangedEventArgs e)
    {
      UploadProgressChangedEventHandler handler = UploadProgressChanged;
      if (handler != null)
        handler (this, e);
    }

    protected virtual void OnUploadStringCompleted (UploadStringCompletedEventArgs args)
    {
      CompleteAsync ();
      UploadStringCompletedEventHandler handler = UploadStringCompleted;
      if (handler != null)
        handler (this, args);
    }

    protected virtual void OnWriteStreamClosed (WriteStreamClosedEventArgs e)
    {
      CompleteAsync ();
      WriteStreamClosedEventHandler handler = WriteStreamClosed;
      if (handler != null)
        handler (this, e);
    }

    protected virtual WebRequest GetWebRequest (Uri address)
    {
      if (address == null)
        throw new ArgumentNullException ("address");

      // if the URI is relative then we use our base address URI to make an absolute one
      Uri uri = address.IsAbsoluteUri ? address : new Uri (new Uri (baseAddress), address);

      HttpWebRequest request = (HttpWebRequest) WebRequest.Create (uri);
      request.AllowReadStreamBuffering = AllowReadStreamBuffering;
      request.AllowWriteStreamBuffering = AllowWriteStreamBuffering;
      request.UseDefaultCredentials = UseDefaultCredentials;

      request.progress = delegate (long read, long length) {
        callback_data.sync_context.Post (delegate (object sender) {
          OnDownloadProgressChanged (new DownloadProgressChangedEventArgs (read, length, callback_data.user_token));
        }, null);

      };
      return request;
    }

    protected virtual WebResponse GetWebResponse (WebRequest request, IAsyncResult result)
    {
      return request.EndGetResponse (result);
    }
  }
}

www.java2v.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.