/* .Net/C#: 实现支持断点续传多线程下载的 Http Web 客户端工具类 (C# DIY HttpWebClient)
* Reflector 了一下 System.Net.WebClient ,改写或增加了若干:
* DownLoad、Upload 相关方法!
* DownLoad 相关改动较大!
* 增加了 DataReceive、ExceptionOccurrs 事件!
* 了解服务器端与客户端交互的 HTTP 协议参阅:
* 使文件下载的自定义连接支持 FlashGet 的断点续传多线程链接下载! JSP/Servlet 实现!
* http://blog.csdn.net/playyuer/archive/2004/08/02/58430.aspx
* 使文件下载的自定义连接支持 FlashGet 的断点续传多线程链接下载! C#/ASP.Net 实现!
* http://blog.csdn.net/playyuer/archive/2004/08/02/58281.aspx
*/
//2005-03-14 修订:
/* .Net/C#: 实现支持断点续传多线程下载的工具类
* Reflector 了一下 System.Net.WebClient ,改写或增加了若干:
* DownLoad、Upload 相关方法!
* 增加了 DataReceive、ExceptionOccurrs　事件
*/
namespace Microshaoft.Utils
{
using System;
using System.IO;
using System.Net;
using System.Text;
using System.Security;
using System.Threading;
using System.Collections.Specialized;
/// <summary>
/// 记录下载的字节位置
/// </summary>
public class DownLoadState
{
private string _FileName;
private string _AttachmentName;
private int _Position;
private string _RequestURL;
private string _ResponseURL;
private int _Length;
private byte[] _Data;
public string FileName
{
get
{
return _FileName;
}
}
public int Position
{
get
{
return _Position;
}
}
public int Length
{
get
{
return _Length;
}
}
public string AttachmentName
{
get
{
return _AttachmentName;
}
}
public string RequestURL
{
get
{
return _RequestURL;
}
}
public string ResponseURL
{
get
{
return _ResponseURL;
}
}
public byte[] Data
{
get
{
return _Data;
}
}
internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName,int Position, int Length, byte[] Data)
{
this._FileName = FileName;
this._RequestURL = RequestURL;
this._ResponseURL = ResponseURL;
this._AttachmentName = AttachmentName;
this._Position = Position;
this._Data = Data;
this._Length = Length;
}
internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName,int Position, int Length, ThreadCallbackHandler tch)
{
this._RequestURL = RequestURL;
this._ResponseURL = ResponseURL;
this._FileName = FileName;
this._AttachmentName = AttachmentName;
this._Position = Position;
this._Length = Length;
this._ThreadCallback = tch;
}
internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName,int Position, int Length)
{
this._RequestURL = RequestURL;
this._ResponseURL = ResponseURL;
this._FileName = FileName;
this._AttachmentName = AttachmentName;
this._Position = Position;
this._Length = Length;
}
private ThreadCallbackHandler _ThreadCallback;
public HttpWebClient httpWebClient
{
get
{
return this._hwc;
}
set
{
this._hwc = value;
}
}
internal Thread thread
{
get
{
return _thread;
}
set
{
_thread = value;
}
}
private HttpWebClient _hwc;
private Thread _thread;
//
internal void StartDownloadFileChunk()
{
if (this._ThreadCallback != null)
{
this._ThreadCallback(this._RequestURL, this._FileName, this._Position, this._Length);
this._hwc.OnThreadProcess(this._thread);
}
}
}
//委托代理线程的所执行的方法签名一致
public delegate void ThreadCallbackHandler(string S, string s, int I, int i);
//异常处理动作
public enum ExceptionActions
{
Throw,
CancelAll,
Ignore,
Retry
}
/// <summary>
/// 包含 Exception 事件数据的类
/// </summary>
public class ExceptionEventArgs : System.EventArgs
{
private System.Exception _Exception;
private ExceptionActions _ExceptionAction;
private DownLoadState _DownloadState;
public DownLoadState DownloadState
{
get
{
return _DownloadState;
}
}
public Exception Exception
{
get
{
return _Exception;
}
}
public ExceptionActions ExceptionAction
{
get
{
return _ExceptionAction;
}
set
{
_ExceptionAction = value;
}
}
internal ExceptionEventArgs(System.Exception e, DownLoadState DownloadState)
{
this._Exception = e;
this._DownloadState = DownloadState;
}
}
/// <summary>
/// 包含 DownLoad 事件数据的类
/// </summary>
public class DownLoadEventArgs : System.EventArgs
{
private DownLoadState _DownloadState;
public DownLoadState DownloadState
{
get
{
return _DownloadState;
}
}
public DownLoadEventArgs(DownLoadState DownloadState)
{
this._DownloadState = DownloadState;
}
}
public class ThreadProcessEventArgs : System.EventArgs
{
private Thread _thread;
public Thread thread
{
get
{
return this._thread;
}
}
public ThreadProcessEventArgs(Thread thread)
{
this._thread = thread;
}
}
/// <summary>
/// 支持断点续传多线程下载的类
/// </summary>
public class HttpWebClient
{
private static object _SyncLockObject = new object();
public delegate void DataReceiveEventHandler(HttpWebClient Sender, DownLoadEventArgs e);
public event DataReceiveEventHandler DataReceive; //接收字节数据事件
public delegate void ExceptionEventHandler(HttpWebClient Sender, ExceptionEventArgs e);
public event ExceptionEventHandler ExceptionOccurrs; //发生异常事件
public delegate void ThreadProcessEventHandler(HttpWebClient Sender, ThreadProcessEventArgs e);
public event ThreadProcessEventHandler ThreadProcessEnd; //发生多线程处理完毕事件
private int _FileLength; //下载文件的总大小
public int FileLength
{
get
{
return _FileLength;
}
}
/// <summary>
/// 分块下载文件
/// </summary>
/// <param name="Address">URL 地址</param>
/// <param name="FileName">保存到本地的路径文件名</param>
/// <param name="ChunksCount">块数,线程数</param>
public void DownloadFile(string Address, string FileName, int ChunksCount)
{
int p = 0; // position
int s = 0; // chunk size
string a = null;
HttpWebRequest hwrq;
HttpWebResponse hwrp = null;
try
{
hwrq = (HttpWebRequest) WebRequest.Create(this.GetUri(Address));
hwrp = (HttpWebResponse) hwrq.GetResponse();
long L = hwrp.ContentLength;
hwrq.Credentials = this.m_credentials;
L = ((L == -1) || (L > 0x7fffffff)) ? ((long) 0x7fffffff) : L; //Int32.MaxValue 该常数的值为 2,147,483,647; 即十六进制的 0x7FFFFFFF
int l = (int) L;
this._FileLength = l;
// 在本地预定空间(竟然在多线程下不用先预定空间)
// FileStream sw = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);
// sw.Write(new byte[l], 0, l);
// sw.Close();
// sw = null;
bool b = (hwrp.Headers["Accept-Ranges"] != null & hwrp.Headers["Accept-Ranges"] == "bytes");
a = hwrp.Headers["Content-Disposition"]; //attachment
if (a != null)
{
a = a.Substring(a.LastIndexOf("filename=") + 9);
}
else
{
a = FileName;
}
int ss = s;
if (b)
{
s = l / ChunksCount;
if (s < 2 * 64 * 1024) //块大小至少为 128 K 字节
{
s = 2 * 64 * 1024;
}
ss = s;
int i = 0;
while (l > s)
{
l -= s;
if (l < s)
{
s += l;
}
if (i++ > 0)
{
DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s, newThreadCallbackHandler(this.DownloadFileChunk));
// 单线程下载
// x.StartDownloadFileChunk();
x.httpWebClient = this;
//多线程下载
Thread t = new Thread(new ThreadStart(x.StartDownloadFileChunk));
//this.OnThreadProcess(t);
t.Start();
}
p += s;
}
s = ss;
byte[] buffer = this.ResponseAsBytes(Address, hwrp, s, FileName);
this.OnThreadProcess(Thread.CurrentThread);
// lock (_SyncLockObject)
// {
// this._Bytes += buffer.Length;
// }
}
}
catch (Exception e)
{
ExceptionActions ea = ExceptionActions.Throw;
if (this.ExceptionOccurrs != null)
{
DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s);
ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
ExceptionOccurrs(this, eea);
ea = eea.ExceptionAction;
}
if (ea == ExceptionActions.Throw)
{
if (!(e is WebException) && !(e is SecurityException))
{
throw new WebException("net_webclient", e);
}
throw;
}
}
}
internal void OnThreadProcess(Thread t)
{
if (ThreadProcessEnd != null)
{
ThreadProcessEventArgs tpea = new ThreadProcessEventArgs(t);
ThreadProcessEnd(this, tpea);
}
}
/// <summary>
/// 下载一个文件块,利用该方法可自行实现多线程断点续传
/// </summary>
/// <param name="Address">URL 地址</param>
/// <param name="FileName">保存到本地的路径文件名</param>
/// <param name="Length">块大小</param>
public void DownloadFileChunk(string Address, string FileName, int FromPosition, int Length)
{
HttpWebResponse hwrp = null;
string a = null;
try
{
//this._FileName = FileName;
HttpWebRequest hwrq = (HttpWebRequest) WebRequest.Create(this.GetUri(Address));
//hwrq.Credentials = this.m_credentials;
hwrq.AddRange(FromPosition);
hwrp = (HttpWebResponse) hwrq.GetResponse();
a = hwrp.Headers["Content-Disposition"]; //attachment
if (a != null)
{
a = a.Substring(a.LastIndexOf("filename=") + 9);
}
else
{
a = FileName;
}
byte[] buffer = this.ResponseAsBytes(Address, hwrp, Length, FileName);
// lock (_SyncLockObject)
// {
// this._Bytes += buffer.Length;
// }
}
catch (Exception e)
{
ExceptionActions ea = ExceptionActions.Throw;
if (this.ExceptionOccurrs != null)
{
DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, FromPosition, Length);
ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
ExceptionOccurrs(this, eea);
ea = eea.ExceptionAction;
}
if (ea == ExceptionActions.Throw)
{
if (!(e is WebException) && !(e is SecurityException))
{
throw new WebException("net_webclient", e);
}
throw;
}
}
}
internal byte[] ResponseAsBytes(string RequestURL, WebResponse Response, long Length, stringFileName)
{
string a = null; //AttachmentName
int P = 0; //整个文件的位置指针
int num2 = 0;
try
{
a = Response.Headers["Content-Disposition"]; //attachment
if (a != null)
{
a = a.Substring(a.LastIndexOf("filename=") + 9);
}
long num1 = Length; //Response.ContentLength;
bool flag1 = false;
if (num1 == -1)
{
flag1 = true;
num1 = 0x10000; //64k
}
byte[] buffer1 = new byte[(int) num1];
int p = 0; //本块的位置指针
string s = Response.Headers["Content-Range"];
if (s != null)
{
s = s.Replace("bytes ", "");
s = s.Substring(0, s.IndexOf("-"));
P = Convert.ToInt32(s);
}
int num3 = 0;
Stream S = Response.GetResponseStream();
do
{
num2 = S.Read(buffer1, num3, ((int) num1) - num3);
num3 += num2;
if (flag1 && (num3 == num1))
{
num1 += 0x10000;
byte[] buffer2 = new byte[(int) num1];
Buffer.BlockCopy(buffer1, 0, buffer2, 0, num3);
buffer1 = buffer2;
}
// lock (_SyncLockObject)
// {
// this._bytes += num2;
// }
if (num2 > 0)
{
if (this.DataReceive != null)
{
byte[] buffer = new byte[num2];
Buffer.BlockCopy