相信接触过网络开发的人对HTTP、HttpWebRequest、Socket这些东西都不陌生吧。它们之间的一些介绍和关系我这里都忽略了。开我们平时开发过程中也是很少有机会接触大什么大并发这个东东，一般大并发我们都需要考虑异步和多线程以及对象池，这个我们以一个简单demo来讲解吧。
主要的调用关系图如下：
类的结构图如下：
一：这里我们依次对这些类做一个简单的说明
HttpRequestInfo：
public string Url：http请求的url字符串，如http://www.baidu.com/
public byte[] PostData：Post请求中的数据
public WebHeaderCollection Headers：请求的头部数据
public bool AllowAutoRedirect ：是否允许301、302自动跳转，如果你想获取请求返回的头部信息，建议一般设置为false
public Dictionary<string, string> ExternalData ：请求过程中附加的数据（如数据记录的ID），便于在成功或失败回调函数中调用
public Action<HttpContextInfo> ActionCompleted ：请求成功后所调用的函数
public Action<HttpRequestException> ActionException：请求失败所调用函数
public HttpRequestInfo Clone()：返回当前对象的一个副本。
HttpResponseInfo：
public Stream ResponseContent ：Http请求返回内容（除头部信息）的对象流
public HttpStatusCode StatusCode：Http返回的状态
public string StatusDescription ：Http状态描述
public WebHeaderCollection Headers：Http返回的头部信息
public string GetString(Encoding coding)：把http返回体中数据流转换为字符串，转换编码就是我们所传参数。
public interface IHttpRequest
{
void GetResponseAsync(HttpRequestInfo request);
bool IsBusy { set; get; }
}
在IHttpRequest接口中，IsBusy属性主要是判断当前对象是否正在使用中，GetResponseAsync方法是真正完成Http请求的方法。
这里我们主要看看HttpRequestFactory的封装吧，管理对象实例的个数，相当于一个对象池，这里的代码主要是基于。net framework2.0的，
首先我们需要2个集合分别管理HttpRequestInfo请求实例和IHttpRequest处理请求实例，
static Queue<HttpRequestInfo> requestTask = new Queue<HttpRequestInfo>();
static List<IHttpRequest> Handlers = new List<IHttpRequest>();
而我们暴露给外部的一个主要方法就是AddRequestTask，
public static void AddRequestTask(HttpRequestInfo info)
{
if (!string.IsNullOrEmpty(info.Url))
{
lock (Lockobj)
{
Interlocked.Increment(ref requestCount);
requestTask.Enqueue(info);
}
}
}
那么这些请求在什么时候被处理了，在一个叫Process方法中处理，
private static void Process(object obj) { while (true) { IHttpRequest handler = GetAvailableHttpRequest(); while (handler == null) { Thread.Sleep(100); handler = GetAvailableHttpRequest(); } HttpRequestInfo task = GetTask(); while (task == null) { Thread.Sleep(100); task = GetTask(); } if (task != null && handler != null) { Interlocked.Decrement(ref requestCount); handler.GetResponseAsync(task); } // Thread.Sleep(10); } }
在这个方法中我们需要调用GetAvailableHttpRequest来获取IHttpRequest处理对象实例，调用GetTask来获取HttpRequestInfo请求实例。如果这2个实例都存在我们调用 IHttpRequest.GetResponseAsync(HttpRequestInfo);方法开始处理http请求。
GetAvailableHttpRequest如下：
private static IHttpRequest GetAvailableHttpRequest() { lock (Lockobj) { for (int i = 0; i < Handlers.Count; i++) { if (!Handlers[i].IsBusy) { return Handlers[i]; } } if (Handlers.Count <= MaxRequestCount) { IHttpRequest handler = (IHttpRequest)Activator.CreateInstance(_httpRequestType); Handlers.Add(handler); return handler; } } return null; //return GetAvailableHttpRequest(); }
在GetAvailableHttpRequest方法中，我们首先在处理对象集合中查找是否有空闲对象，如果有就返回，否则检查当前对象实例个数个数是否达到最大个数，如果没有我们则创建新实例，且加入到集合中，再返回，否者返回null。所以在Process方法中有一个检查，看啊看你返回的IHttpRequest是否为null，请注意这里一定不要用递归来返回有效的IHttpRequest，建议用一个死循环来处理，如果用递归一般不会出现什么问题，但是递归层次嵌套太深就会出现栈溢出错误，我在测试的时候曾经出现过这个问题。GetTask和GetAvailableHttpRequest处理一样。
那么这里的Process方法有在什么地方调用了，在HttpRequestFactory的静态构造函数中调用。
static HttpRequestFactory()
{
MaxRequestCount = 10;
ThreadPool.QueueUserWorkItem(new WaitCallback(Process));
}
到这里我们的一个对象池就构造玩了。
二 现在我们来看看RequestHttpWebRequest是如何处理HTTP请求的。它主要使用HttpWebRequest来处理请求。
这里我们主要使用HttpWebRequest的异步方法，因此我们需要构造一个状态对象StateObjectInfo
class StateObjectInfo : HttpContextInfo
{
internal byte[] Buffer { set; get; } //把返回的流写到HttpResponseInfo.ResponseContent 时用到的暂存数组
internal Stream ReadStream { set; get; }//把返回的流写到HttpResponseInfo.ResponseContent
internal HttpWebRequest HttpWebRequest { set; get; }
internal RequestHttpWebRequest RequestHandler { set; get; }//主要便于后面改IsBusy属性。
}
其GetResponseAsync实现如下：
public void GetResponseAsync(HttpRequestInfo info) { HttpWebRequest webRequest; StateObjectInfo state; InitWebRequest(info, out webRequest, out state); try { if (IsHttpPost) { webRequest.Method = "POST"; webRequest.ContentType = "application/x-www-form-urlencoded"; webRequest.BeginGetRequestStream(EndRequest, state); } else { webRequest.BeginGetResponse(EndResponse, state); } } catch (Exception ex) { HandException(ex, state); } }
其中InitWebRequest的实现如下：
private void InitWebRequest(HttpRequestInfo info, out HttpWebRequest webRequest, out StateObjectInfo state) { IsBusy = true; if (info.PostData != null && info.PostData.Length > 0) { IsHttpPost = true; } else { IsHttpPost = false; } if (info.Url.ToLower().Trim().StartsWith("https")) { IsHttps = true; ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult); ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3; } else { IsHttps = false; } webRequest = HttpWebRequest.CreateDefault(new Uri(info.Url)) as HttpWebRequest; if (IsHttps) { /*基础连接已经关闭: 发送时发生错误 */ /*无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接*/ webRequest.KeepAlive = false; webRequest.ProtocolVersion = HttpVersion.Version10; webRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)"; } webRequest.AllowAutoRedirect = info.AllowAutoRedirect; if (info.Headers != null && info.Headers.Count > 0) { foreach (string key in info.Headers.Keys) { webRequest.Headers.Add(key, info.Headers[key]); } } //webRequest.Proxy = WebProxy.GetDefaultProxy(); //webRequest.Proxy.Credentials = CredentialCache.DefaultCredentials; //webResponse.Headers.Get("Set-Cookie"); state = new StateObjectInfo { Buffer = new byte[1024 * 1024], HttpWebRequest = webRequest, RequestHandler = this, RequestInfo = info, ResponseInfo = new HttpResponseInfo() }; }
关于该类的EndRequest、EndResponse我想就没什么说的了，其中ReadCallBack的实现如下：
void ReadCallBack(IAsyncResult ar) { StateObjectInfo state = ar.AsyncState as StateObjectInfo; try { int read = state.ReadStream.EndRead(ar); if (read > 0) { state.ResponseInfo.ResponseContent.Write(state.Buffer, 0, read); state.ReadStream.BeginRead(state.Buffer, 0, state.Buffer.Length, ReadCallBack, state); } else { state.ReadStream.Close(); state.HttpWebRequest.Abort(); if (state.RequestInfo.ActionCompleted != null) { state.ResponseInfo.ResponseContent.Seek(0, SeekOrigin.Begin); state.RequestInfo.ActionCompleted(state); } state.Buffer = null; state.RequestHandler.IsBusy = false; } } catch (Exception ex) { HandException(ex, state); } }
这里还有一个HandException方法需要我们注意：
private void HandException(Exception ex, StateObjectInfo state) { if (state.ReadStream != null) state.ReadStream.Close(); if (state.HttpWebRequest != null) state.HttpWebRequest.Abort(); state.Buffer = null; if (state.RequestInfo.ActionException != null) { state.RequestInfo.ActionException(new HttpRequestException(state, ex)); } state.RequestHandler.IsBusy = false; }
这里我们在使用HttpWebRequest的时候，在完成使用后一定要关闭请求流。
在我们来看看一个简单的调用把：
public static void DownLoadFile(string remoteurl, string destinationFilePath, string id) { try { if (HasIllegalCharacters(destinationFilePath, false)) { SetFileCopyed(id, "400", "HasIllegalCharacters"); return; } DirectoryInfo dir = new DirectoryInfo(destinationFilePath); FileInfo destinationFile = new FileInfo(destinationFilePath); if (!destinationFile.Directory.Exists) { destinationFile.Directory.Create(); } HttpRequestInfo request = new HttpRequestInfo(remoteurl); request.ActionCompleted = new Action<HttpContextInfo>(x => { if (x.ResponseInfo.StatusCode == HttpStatusCode.OK) { using (Stream wr = File.Open(destinationFilePath, FileMode.OpenOrCreate, FileAccess.Write), sr = x.ResponseInfo.ResponseContent) { byte[] data = new byte[1024 * 1024]; int readcount = sr.Read(data, 0, data.Length); while (readcount > 0) { wr.Write(data, 0, readcount); readcount = sr.Read(data, 0, data.Length); } } SetFileCopyed(id, "200", string.Empty); } else { SetFileCopyed(id, ((int)x.ResponseInfo.StatusCode).ToString(), x.ResponseInfo.StatusDescription); string message = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " : " + remoteurl + " : " + x.ResponseInfo.StatusDescription; LogManager.LogException(message); } }); request.ActionException = new Action<HttpRequestException>(ex => { Regex reg = new Regex(@"\d{3}",RegexOptions.Compiled); string message = ex.Message; Match m = reg.Match(message); if (m.Success) { SetFileCopyed(id, m.Value, message); } else { SetFileCopyed(id, "503", message); HttpRequestInfo newRequest = ex.HttpContextInfo.RequestInfo.Clone(); request.ActionCompleted = null; request.ActionException = null; HttpRequestFactory.AddRequestTask(newRequest); } message = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " : " + ex.HttpContextInfo.RequestInfo.Url + " : " + message; LogManager.LogException(message); }); HttpRequestFactory.AddRequestTask(request); } catch (Exception ex) { SetFileCopyed(id, "-1", ex.Message); string message = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " : " + remoteurl + " : " + ex.Message; LogManager.LogException(message); } } internal static bool HasIllegalCharacters(string path, bool checkAdditional) { for (int i = 0; i < path.Length; i++) { int num2 = path[i]; if (((num2 == 0x22) || (num2 == 60)) || (((num2 == 0x3e) || (num2 == 0x7c)) || (num2 < 0x20))) { return true; } if (checkAdditional && ((num2 == 0x3f) || (num2 == 0x2a))) { return true; } } return false; }
对于这个调用的demo我这里就不多说，不过在调用的时候偶尔会出现：
/*基础连接已经关闭: 发送时发生错误 */
/*无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接*/
这样的错误，网上有一些什么改良方法，我测试后都不管用，个人猜测是与网络有关的，即使我用socket来做偶尔也会有一些问题。所以当我们遇到这些网络问题的时候，我们把我们的请求再次加入请求队列中 HttpRequestFactory.AddRequestTask(newRequest);。这一很重要的哦。
HttpWebRequest类对我们做http请求做了很多封装，我们使用也很方便。但是它的性能比我们自己用socket要低很多，同时在一些处理上违背了我们的操作习惯。如我们上面的调用代码：
如果我们http返回状态是403、404...（除200以外）程序没有进入我的else，而是进入我的ActionException方法里面了，这点让我很是不爽。于是萌生了用socket来做http请求的念头。
三 现在我们来看看SocketHttpRequest是如何处理HTTP请求的。它主要使用Socket来处理请求。
SocketHttpRequest和RequestHttpWebRequest一样都是采用对象的异步模式，那么也需要一个状态对象：
class RequestSockeStateObject : HttpContextInfo
{
internal SocketHttpRequest RequestHandler { set; get; }
internal Socket _socket { set; get; } //普通http请求采用socket
internal List<byte> HeaderBuffer { set; get; }
internal byte[] Buffer { set; get; }
internal int ContentLength { set; get; }//http需要接收的数据长度
internal int ReceiveLength { set; get; }//http已经接收的数据长度
internal SslStream SslStream { set; get; }//https请求采用TcpClient，这里需要用到SslStream
}
public void GetResponseAsync(HttpRequestInfo info)
{
RequestSockeStateObject _state;
InitRequestSockeStateObject(info, out _state);
SocketConnection(_state);
}
这里的InitRequestSockeStateObject和RequestHttpWebRequest的InitWebRequest方法差不多，就不在累赘了。
主要看看SocketConnection方法：
void SocketConnection(RequestSockeStateObject _state) { try { Uri uri = new Uri(_state.RequestInfo.Url); IPHostEntry hostEntry = Dns.GetHostEntry(uri.Host); if (IsHttps) { TcpClient tcpclient = new TcpClient(); tcpclient.Connect(hostEntry.AddressList, uri.Port); _state._socket = tcpclient.Client; SslStream sslStream = new SslStream(tcpclient.GetStream(), false, new RemoteCertificateValidationCallback(ValidateServerCertificate), null); sslStream.AuthenticateAsClient(hostEntry.HostName, new X509CertificateCollection(), SslProtocols.Ssl3 | SslProtocols.Tls, false); _state.SslStream = sslStream; Begin_Write(_state); } else { Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); client.Connect(hostEntry.AddressList, uri.Port); _state._socket = client; BeginSend(_state); } } catch (Exception ex) { HandException(ex, _state); } }
socket连接是需要IP和端口的，这里我们借用 Uri来获取所需端口，但是一台计算机的ip可能有很多个，实际只有一两个可以连接，所以我们这里需要调用 client.Connect(hostEntry.AddressList, uri.Port)方法，传递一个ip集合。如果是https的话，直接用socket我没有搞定，最后用SslStream搞定，不知道大家有没有其他方法。
其中Begin_Write、End_Write、Complete_Read方法是sslStream异步中所必需的方法，BeginSend、Send_Completed、Receive_Completed、RepeatReceive是socket异步中所需方法。其中Complete_Read和Receive_Completed方法相似。
protected virtual void Complete_Read(IAsyncResult ar) { RequestSockeStateObject state = ar.AsyncState as RequestSockeStateObject; try { int byteCount = state.SslStream.EndRead(ar); if (state.ResponseInfo.Headers.Count < 1) { SetResponseHeaders(state, byteCount); if ((state.ReceiveLength == state.ContentLength && state.ContentLength > 0)) { EndReceive(state); } else { state.SslStream.BeginRead(state.Buffer, 0, state.Buffer.Length, Complete_Read, state); } } else { if (byteCount > 0 && byteCount==state.Buffer.Length) { state.ResponseInfo.ResponseContent.Write(state.Buffer, 0, byteCount); state.SslStream.BeginRead(state.Buffer, 0, state.Buffer.Length, Complete_Read, state); } else { state.ResponseInfo.ResponseContent.Write(state.Buffer, 0, byteCount); EndReceive(state); } } } catch (Exception ex) { HandException(ex, state); } }
如果是第一次接收数据流，我们必须把数据流中http头部信息取出来，再把头部信息以外的数据流写到HttpResponseInfo.ResponseContent中，如果我们已经接收的数据等于我们需要接收的数据，就表示我们已经接收完毕了。如果没有就继续接收数据。在第二次及以后所接收数据过程中，我们需要判断接收数据长度是否小于接收数组的长度，如果小于就表示接收完毕了，否则继续接收。这里的EndReceive方法如下：
void EndReceive(RequestSockeStateObject state) { /* * if (state.RequestInfo.AllowAutoRedirect && (state.ResponseInfo.StatusCode == HttpStatusCode.Found || state.ResponseInfo.StatusCode == HttpStatusCode.MovedPermanently)) { string location = state.ResponseInfo.Headers["Location"]; state.RequestInfo.Url = location; state.RequestInfo.Headers = state.ResponseInfo.Headers; state.RequestInfo.Headers.Remove("Location"); state.RequestInfo.Headers.Add("Referer", location); Begin_Write(state); } */ if (IsHttps) { state.SslStream.Close(); state.SslStream = null; } else { state._socket.Shutdown(SocketShutdown.Both); state._socket.Close(); state._socket = null; } if (state.RequestInfo.ActionCompleted != null) { state.ResponseInfo.ResponseContent.Seek(0, SeekOrigin.Begin); state.RequestInfo.ActionCompleted(state); } state.RequestHandler.IsBusy = false; }
EndReceive方法主要是关闭socket或则SslStream数据流，然后调用ActionCompleted方法。在这里 state.ResponseInfo.ResponseContent.Seek(0,
SeekOrigin.Begin);这个方法非常重要，不然在外面的调用方法就必须调用Stream.Seek(0, SeekOrigin.Begin)来吧数据流定位开始位置。
在SocketHttpRequest这个类中，我们是如何来获取发送的http请求信息以及如何解析http返回的header信息了？
首先来看一个GetRequestData方法，它主要是通过RequestInfo实例来获取请求信息：
byte[] GetRequestData(RequestSockeStateObject _state) { StringBuilder bufRequest = new StringBuilder(); Uri uri = new Uri(_state.RequestInfo.Url); if (!IsHttpPost) { bufRequest.Append("GET ").Append(uri.OriginalString).AppendLine(" HTTP/1.1"); } else { bufRequest.Append("POST ").Append(uri.OriginalString).AppendLine(" HTTP/1.1"); string contentLengthkey = "Content-Length"; string contentTypekey = "Content-Type"; List<string> headerKeys = new List<string>(_state.RequestInfo.Headers.AllKeys); if (headerKeys.Contains(contentLengthkey)) { _state.RequestInfo.Headers.Remove(contentLengthkey); } if (headerKeys.Contains(contentTypekey)) { _state.RequestInfo.Headers.Remove(contentTypekey); } _state.RequestInfo.Headers.Add(contentTypekey, "application/x-www-form-urlencoded"); _state.RequestInfo.Headers.Add(contentLengthkey, _state.RequestInfo.PostData.Length.ToString()); } _state.RequestInfo.Headers.Add("Host", uri.Host); _state.RequestInfo.Headers.Add("Connection", "keep-alive"); if (_state.RequestInfo.Headers.Count > 0) { bufRequest.Append(_state.RequestInfo.Headers.ToString()); } byte[] byteData = Encoding.ASCII.GetBytes(bufRequest.ToString()); if (!IsHttpPost) { return byteData; } else { byte[] sendData = new byte[byteData.Length + _state.RequestInfo.PostData.Length]; Array.Copy(byteData, 0, sendData, 0, byteData.Length); Array.Copy(_state.RequestInfo.PostData, 0, sendData, byteData.Length, _state.RequestInfo.PostData.Length); return sendData; } }
有关请求和header信息的字符串建议不要自己拼接，用WebHeaderCollection实例的ToString方法来生成，并且它把最后那个回车换行也生成。
那么如何更具换回的流中的数据来设置它的返回头信息了，这里我们有一个方法SetResponseHeaders：
void SetResponseHeaders(RequestSockeStateObject state, int bytesRead) { try { byte[] tempArray = new byte[bytesRead]; Array.Copy(state.Buffer, 0, tempArray, 0, bytesRead); state.HeaderBuffer.AddRange(tempArray); tempArray = state.HeaderBuffer.ToArray(); string headerSpilt = "\r\n\r\n"; byte[] headerbyte = Encoding.ASCII.GetBytes(headerSpilt); int contentindex = DestTag(tempArray, headerbyte, 0, tempArray.Length); if (contentindex > 0) { string headerStr = Encoding.ASCII.GetString(tempArray, 0, contentindex); int startIndex = contentindex + headerbyte.Length; SetResponseHeaders(headerStr, state); state.ReceiveLength = tempArray.Length - startIndex; state.ResponseInfo.ResponseContent.Write(tempArray, startIndex, tempArray.Length - startIndex); state.HeaderBuffer.Clear(); } } catch (Exception ex) { HandException(ex, state); } }
这里的bytesRead时我第一次接收的数据流长度，首先我们需要在返回流中找到连续的\r\n\r\n 信息，它前面是返回头信息，后面的时返回体信息。这里我们用自定义的DestTag方法来查找。SetResponseHeaders方法如下：
void SetResponseHeaders(string headerStr, RequestSockeStateObject state) { try { string[] headers = headerStr.Split(new string[] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries); string statline = headers[0]; state.ResponseInfo.StatusCode = GetStatusCode(statline); for (int i = 1; i < headers.Length; i++) { int index = headers[i].IndexOf(":"); if (index > 1) { string key = headers[i].Substring(0, index); string value = headers[i].Substring(index + 1); state.ResponseInfo.Headers.Add(key.Trim(), value.Trim()); } } string contentLength = state.ResponseInfo.Headers["Content-Length"]; state.ContentLength = int.Parse(contentLength); state.ReceiveLength = 0; } catch (Exception ex) { HandException(ex, state); } }
以上就是这个类的主要方法,目前SocketHttpRequest对301、302暂不支持。
完整的代码如下：
namespace HttpRequest
{
using System;
using System.Collections.Generic;
using System.Text;
using System.Net;[Serializable]
public class HttpRequestInfo
{
public HttpRequestInfo(string url)
{
Url = url;
Headers = new WebHeaderCollection();
ExternalData = new Dictionary<string, string>();
}
public string Url { set; get; }
public byte[] PostData { set; get; }
public WebHeaderCollection Headers { set; get; }
public bool AllowAutoRedirect { set; get; }
public Dictionary<string, string> ExternalData { set; get; }
public Action<HttpContextInfo> ActionCompleted { set; get; }
public Action<HttpRequestException> ActionException { set; get; }public HttpRequestInfo Clone()
{
HttpRequestInfo newobj = new HttpRequestInfo(this.Url)
{
AllowAutoRedirect = this.AllowAutoRedirect,
ActionCompleted = this.ActionCompleted,
ActionException = this.ActionException
};
if (PostData != null && PostData.Length > 0)
{
newobj.PostData = new byte[this.PostData.Length];
Array.Copy(this.PostData, 0, newobj.PostData, 0, this.PostData.Length);
}
if (Headers.Count > 0)
{
foreach (string key in Headers.Keys)
{
newobj.Headers.Add(key, Headers[key]);
}
}
if (ExternalData.Count > 0)
{
foreach (string key in ExternalData.Keys)
{
newobj.ExternalData.Add(key, ExternalData[key]);
}
}
return newobj;
}
}
public class HttpRequestException : Exception
{
public HttpRequestException(HttpContextInfo context, Exception ex)
: base(ex.Message, ex)
{
HttpContextInfo = context;
}
public HttpContextInfo HttpContextInfo { set; get; }
}
}
namespace HttpRequest
{
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Net;[Serializable]
public class HttpResponseInfo
{
public HttpResponseInfo()
{
ResponseContent = new MemoryStream();
Headers = new WebHeaderCollection();
}
public Stream ResponseContent { set; get; }
HttpStatusCode _statusCode;
public HttpStatusCode StatusCode
{
set
{
_statusCode = value;
StatusDescription = System.Web.HttpWorkerRequest.GetStatusDescription((int)_statusCode);
}
get
{
return _statusCode;
}
}
public string StatusDescription { set; get; }
public WebHeaderCollection Headers { set; get; }
public string GetString(Encoding coding)
{
StringBuilder str = new StringBuilder();
Stream sr = ResponseContent;
byte[] data = new byte[1024 * 100];
int readcount = sr.Read(data, 0, data.Length);
while (readcount > 0)
{
str.Append(coding.GetString(data, 0, readcount));
readcount = sr.Read(data, 0, data.Length);
}
ResponseContent.Seek(0, SeekOrigin.Begin);
return str.ToString();
}
}public class HttpContextInfo
{
public HttpResponseInfo ResponseInfo { set; get; }
public HttpRequestInfo RequestInfo { set; get; }
}
public interface IHttpRequest
{
void GetResponseAsync(HttpRequestInfo request);
bool IsBusy { set; get; }
}
}
namespace HttpRequest
{
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Data;
using System.Data.OleDb;
using System.Net;
using System.Xml;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;public class RequestHttpWebRequest : IHttpRequest
{
class StateObjectInfo : HttpContextInfo
{
internal byte[] Buffer { set; get; }
internal Stream ReadStream { set; get; }
internal HttpWebRequest HttpWebRequest { set; get; }
internal RequestHttpWebRequest RequestHandler { set; get; }
}private bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
{
//直接确认，否则打不开
return true;
}
public void GetResponseAsync(HttpRequestInfo info)
{
HttpWebRequest webRequest;
StateObjectInfo state;
InitWebRequest(info, out webRequest, out state);
try
{
if (IsHttpPost)
{
webRequest.Method = "POST";
webRequest.ContentType = "application/x-www-form-urlencoded";
webRequest.BeginGetRequestStream(EndRequest, state);
}
else
{
webRequest.BeginGetResponse(EndResponse, state);
}
}
catch (Exception ex)
{
HandException(ex, state);
}
}
void EndRequest(IAsyncResult ar)
{
StateObjectInfo state = ar.AsyncState as StateObjectInfo;
try
{
HttpWebRequest webRequest = state.HttpWebRequest as HttpWebRequest;
using (Stream stream = webRequest.EndGetRequestStream(ar))
{
byte[] data = state.RequestInfo.PostData;
stream.Write(data, 0, data.Length);
}
webRequest.BeginGetResponse(EndResponse, state);
}
catch (Exception ex)
{
HandException(ex, state);
}
}
void EndResponse(IAsyncResult ar)
{
StateObjectInfo state = ar.AsyncState as StateObjectInfo;
try
{
HttpWebResponse webResponse = state.HttpWebRequest.EndGetResponse(ar) as HttpWebResponse;
state.ResponseInfo.StatusCode = webResponse.StatusCode;
state.ResponseInfo.StatusDescription = webResponse.StatusDescription;
foreach (string key in webResponse.Headers.AllKeys)
{
state.ResponseInfo.Headers.Add(key, webResponse.Headers[key]);
}
state.ReadStream = webResponse.GetResponseStream();
state.ReadStream.BeginRead(state.Buffer, 0, state.Buffer.Length, ReadCallBack, state);
}
catch (Exception ex)
{
HandException(ex, state);
}
}
void ReadCallBack(IAsyncResult ar)
{
StateObjectInfo state = ar.AsyncState as StateObjectInfo;
try
{
int read = state.ReadStream.EndRead(ar);
if (read > 0)
{
state.ResponseInfo.ResponseContent.Write(state.Buffer, 0, read);
state.ReadStream.BeginRead(state.Buffer, 0, state.Buffer.Length, ReadCallBack, state);
}
else
{
state.ReadStream.Close();
state.HttpWebRequest.Abort();
if (state.RequestInfo.ActionCompleted != null)
{
state.ResponseInfo.ResponseContent.Seek(0, SeekOrigin.Begin);
state.RequestInfo.ActionCompleted(state);
}
state.Buffer = null;
state.RequestHandler.IsBusy = false;
}
}
catch (Exception ex)
{
HandException(ex, state);
}
}
private void InitWebRequest(HttpRequestInfo info, out HttpWebRequest webRequest, out StateObjectInfo state)
{
IsBusy = true;
if (info.PostData != null && info.PostData.Length > 0)
{
IsHttpPost = true;
}
else
{
IsHttpPost = false;
}
if (info.Url.ToLower().Trim().StartsWith("https"))
{
IsHttps = true;
ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
}
else
{
IsHttps = false;
}
webRequest = HttpWebRequest.CreateDefault(new Uri(info.Url)) as HttpWebRequest;
if (IsHttps)
{
/*基础连接已经关闭: 发送时发生错误 */
/*无法从传输连接中读取数据: 远程主机强迫关闭了一个现有的连接*/
webRequest.KeepAlive = false;
webRequest.ProtocolVersion = HttpVersion.Version10;
webRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";
}
webRequest.AllowAutoRedirect = info.AllowAutoRedirect;
if (info.Headers != null && info.Headers.Count > 0)
{
foreach (string key in info.Headers.Keys)
{
webRequest.Headers.Add(key, info.Headers[key]);
}
}
//webRequest.Proxy = WebProxy.GetDefaultProxy();
//webRequest.Proxy.Credentials = CredentialCache.DefaultCredentials;
//webResponse.Headers.Get("Set-Cookie");
state = new StateObjectInfo
{
Buffer = new byte[1024 * 100],
HttpWebRequest = webRequest,
RequestHandler = this,
RequestInfo = info,
ResponseInfo = new HttpResponseInfo()};
}
private bool IsHttpPost { set; get; }
private bool IsHttps { set; get; }
public bool IsBusy { set; get; }
private void HandException(Exception ex, StateObjectInfo state)
{
if (state.ReadStream != null)
state.ReadStream.Close();
if (state.HttpWebRequest != null)
state.HttpWebRequest.Abort();
state.Buffer = null;
if (state.RequestInfo.ActionException != null)
{
state.RequestInfo.ActionException(new HttpRequestException(state, ex));
}
state.RequestHandler.IsBusy = false;
}
}
}namespace HttpRequest
{
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Net;
public class HttpRequestFactory
{
static HttpRequestFactory()
{
MaxRequestCount = 10;
ThreadPool.QueueUserWorkItem(new WaitCallback(Process));
}static readonly object Lockobj = new object();
static long requestCount = 0;
static Queue<HttpRequestInfo> requestTask = new Queue<HttpRequestInfo>();
static List<IHttpRequest> Handlers = new List<IHttpRequest>();public static void AddRequestTask(HttpRequestInfo info)
{
if (!string.IsNullOrEmpty(info.Url))
{
lock (Lockobj)
{
requestTask.Enqueue(info);
Interlocked.Increment(ref requestCount);
}
}
}private static IHttpRequest GetAvailableHttpRequest()
{
lock (Lockobj)
{
for (int i = 0; i < Handlers.Count; i++)
{
if (!Handlers[i].IsBusy)
{
return Handlers[i];
}
}
if (Handlers.Count <= MaxRequestCount)
{
IHttpRequest handler = (IHttpRequest)Activator.CreateInstance(_httpRequestType);
Handlers.Add(handler);
return handler;
}
}
return null;
//return GetAvailableHttpRequest();
}private static HttpRequestInfo GetTask()
{
HttpRequestInfo task = null;
lock (Lockobj)
{
if (requestTask.Count > 0)
{
task = requestTask.Dequeue();
return task;
}
}
return task;
}private static void Process(object obj)
{
while (true)
{
IHttpRequest handler = GetAvailableHttpRequest();
while (handler == null)
{
Thread.Sleep(500);
handler = GetAvailableHttpRequest();
}
HttpRequestInfo task = GetTask();
while (task == null)
{
Thread.Sleep(500);
task = GetTask();
}
if (task != null && handler != null)
{
handler.GetResponseAsync(task);
Interlocked.Decrement(ref requestCount);
Thread.Sleep(50);
}
}}
public static long TaskCount
{
get
{
return Interlocked.Read(ref requestCount);
}
}
static int _maxRequestCount = 2;
public static int MaxRequestCount
{
set
{
_maxRequestCount = value;
ServicePointManager.DefaultConnectionLimit = _maxRequestCount * 2;
}
get
{
return _maxRequestCount;
}
}static Type _httpRequestType = typeof(RequestHttpWebRequest);
public static void SetHttpRequestType(Type type)
{
if (type.IsCla