实现支持断点续传多线程下载的 Http Web 客户端C#工具类

/* .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;
 
///
/// 记录下载的字节位置
///
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,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,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
}
 
///
/// 包含 Exception 事件数据的类
///
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;
}
}
 
///
/// 包含 DownLoad 事件数据的类
///
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;
}
 
}
 
///
/// 支持断点续传多线程下载的类
///
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;
}
}
 
///
/// 分块下载文件
///
/// URL 地址
/// 保存到本地的路径文件名
/// 块数,线程数
public void DownloadFile(string Address,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],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 s)
{
l -= s;
if (l 0)
{
DownLoadState x = new DownLoadState(Address,hwrp.ResponseUri.AbsolutePath,FileName,a,p,s,new ThreadCallbackHandler(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,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,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);
}
}
 
///
/// 下载一个文件块,利用该方法可自行实现多线程断点续传
///
/// URL 地址
/// 保存到本地的路径文件名
/// 块大小
public void DownloadFileChunk(string Address,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,Length,FileName);
// lock (_SyncLockObject)
// {
// this._Bytes += buffer.Length;
// }
}
catch (Exception e)
{
ExceptionActions ea = ExceptionActions.Throw;
if (this.ExceptionOccurrs != null)
{
DownLoadState x = new DownLoadState(Address,FromPosition,Length);
ExceptionEventArgs eea = new ExceptionEventArgs(e,e);
}
throw;
}
}
}
 
internal byte[] ResponseAsBytes(string RequestURL,WebResponse Response,long Length,string FileName)
{
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,buffer2,num3);
buffer1 = buffer2;
}
 
// lock (_SyncLockObject)
// {
// this._bytes += num2;
// }
if (num2 > 0)
{
if (this.DataReceive != null)
{
byte[] buffer = new byte[num2];
Buffer.BlockCopy(buffer1,buffer,buffer.Length);
DownLoadState dls = new DownLoadState(RequestURL,Response.ResponseUri.AbsolutePath,P,num2,buffer);
DownLoadEventArgs dlea = new DownLoadEventArgs(dls);
//触发事件
this.OnDataReceive(dlea);
//System.Threading.Thread.Sleep(100);
 
}
p += num2; //本块的位置指针
P += num2; //整个文件的位置指针
}
else
{
break;
}
 
}
while (num2 != 0);
 
S.Close();
S = null;
if (flag1)
{
byte[] buffer3 = new byte[num3];
Buffer.BlockCopy(buffer1,buffer3,num3);
buffer1 = buffer3;
}
return buffer1;
}
catch (Exception e)
{
ExceptionActions ea = ExceptionActions.Throw;
if (this.ExceptionOccurrs != null)
{
DownLoadState x = new DownLoadState(RequestURL,num2);
ExceptionEventArgs eea = new ExceptionEventArgs(e,e);
}
throw;
}
return null;
}
}
 
private void OnDataReceive(DownLoadEventArgs e)
{
//触发数据到达事件
DataReceive(this,e);
}
 
public byte[] UploadFile(string address,string fileName)
{
return this.UploadFile(address,"POST",fileName,"file");
}
 
public string UploadFileEx(string address,string method,string fileName,string fieldName)
{
return Encoding.ASCII.GetString(UploadFile(address,method,fieldName));
}
 
public byte[] UploadFile(string address,string fieldName)
{
byte[] buffer4;
FileStream stream1 = null;
try
{
fileName = Path.GetFullPath(fileName);
string text1 = "---------------------" + DateTime.Now.Ticks.ToString("x");
 
string text2 = "application/octet-stream";
 
stream1 = new FileStream(fileName,FileMode.Open,FileAccess.Read);
WebRequest request1 = WebRequest.Create(this.GetUri(address));
request1.Credentials = this.m_credentials;
request1.ContentType = "multipart/form-data; boundary=" + text1;
 
request1.Method = method;
string[] textArray1 = new string[7] {"--",text1,"rnContent-Disposition: form-data; name="" + fieldName + ""; filename="",Path.GetFileName(fileName),""rnContent-Type: ",text2,"rnrn"};
string text3 = string.Concat(textArray1);
byte[] buffer1 = Encoding.UTF8.GetBytes(text3);
byte[] buffer2 = Encoding.ASCII.GetBytes("rn--" + text1 + "rn");
long num1 = 0x7fffffffffffffff;
try
{
num1 = stream1.Length;
request1.ContentLength = (num1 + buffer1.Length) + buffer2.Length;
}
catch
{
}
byte[] buffer3 = new byte[Math.Min(0x2000,(int) num1)];
using (Stream stream2 = request1.GetRequestStream())
{
int num2;
stream2.Write(buffer1,buffer1.Length);
do
{
num2 = stream1.Read(buffer3,buffer3.Length);
if (num2 != 0)
{
stream2.Write(buffer3,num2);
}
}
while (num2 != 0);
stream2.Write(buffer2,buffer2.Length);
}
stream1.Close();
stream1 = null;
WebResponse response1 = request1.GetResponse();
 
buffer4 = this.ResponseAsBytes(response1);
}
catch (Exception exception1)
{
if (stream1 != null)
{
stream1.Close();
stream1 = null;
}
if (!(exception1 is WebException) && !(exception1 is SecurityException))
{
//throw new WebException(SR.GetString("net_webclient"),exception1);
throw new WebException("net_webclient",exception1);
}
throw;
}
return buffer4;
}
 
private byte[] ResponseAsBytes(WebResponse response)
{
int num2;
long num1 = response.ContentLength;
bool flag1 = false;
if (num1 == -1)
{
flag1 = true;
num1 = 0x10000;
}
byte[] buffer1 = new byte[(int) num1];
Stream stream1 = response.GetResponseStream();
int num3 = 0;
do
{
num2 = stream1.Read(buffer1,((int) num1) - num3);
num3 += num2;
if (flag1 && (num3 == num1))
{
num1 += 0x10000;
byte[] buffer2 = new byte[(int) num1];
Buffer.BlockCopy(buffer1,num3);
buffer1 = buffer2;
}
}
while (num2 != 0);
stream1.Close();
if (flag1)
{
byte[] buffer3 = new byte[num3];
Buffer.BlockCopy(buffer1,num3);
buffer1 = buffer3;
}
return buffer1;
}
 
private NameValueCollection m_requestParameters;
private Uri m_baseAddress;
private ICredentials m_credentials = CredentialCache.DefaultCredentials;
 
public ICredentials Credentials
{
get
{
return this.m_credentials;
}
set
{
this.m_credentials = value;
}
}
 
public NameValueCollection QueryString
{
get
{
if (this.m_requestParameters == null)
{
this.m_requestParameters = new NameValueCollection();
}
return this.m_requestParameters;
}
set
{
this.m_requestParameters = value;
}
}
 
public string BaseAddress
{
get
{
if (this.m_baseAddress != null)
{
return this.m_baseAddress.ToString();
}
return string.Empty;
}
set
{
if ((value == null) || (value.Length == 0))
{
this.m_baseAddress = null;
}
else
{
try
{
this.m_baseAddress = new Uri(value);
}
catch (Exception exception1)
{
throw new ArgumentException("value",exception1);
}
}
}
}
 
private Uri GetUri(string path)
{
Uri uri1;
try
{
if (this.m_baseAddress != null)
{
uri1 = new Uri(this.m_baseAddress,path);
}
else
{
uri1 = new Uri(path);
}
if (this.m_requestParameters == null)
{
return uri1;
}
StringBuilder builder1 = new StringBuilder();
string text1 = string.Empty;
for (int num1 = 0; num1 < this.m_requestParameters.Count; num1++)
{
builder1.Append(text1 + this.m_requestParameters.AllKeys[num1] + "=" + this.m_requestParameters[num1]);
text1 = "&";
}
UriBuilder builder2 = new UriBuilder(uri1);
builder2.Query = builder1.ToString();
uri1 = builder2.Uri;
}
catch (UriFormatException)
{
uri1 = new Uri(Path.GetFullPath(path));
}
return uri1;
}
 
}
 
}
 
///
/// 测试类
///
class AppTest
{
int _k = 0;
int _K = 0;
 
static void Main()
{
AppTest a = new AppTest();
Microshaoft.Utils.HttpWebClient x = new Microshaoft.Utils.HttpWebClient();
 
a._K = 10;
 
//订阅 DataReceive　事件
x.DataReceive += new Microshaoft.Utils.HttpWebClient.DataReceiveEventHandler(a.x_DataReceive);
//订阅 ExceptionOccurrs　事件
x.ExceptionOccurrs += new Microshaoft.Utils.HttpWebClient.ExceptionEventHandler(a.x_ExceptionOccurrs);
 
x.ThreadProcessEnd += new Microshaoft.Utils.HttpWebClient.ThreadProcessEventHandler(a.x_ThreadProcessEnd);
string F = "http://localhost/download/phpMyAdmin-2.6.1-pl2.zip";
a._F = F;
F = "http://localhost/download/jdk-1_5_0_01-windows-i586-p.aa.exe";
 
string f = F.Substring(F.LastIndexOf("/") + 1);
 
//(new System.Threading.Thread(new System.Threading.ThreadStart(new ThreadProcessState(F,@"E:temp" + f,10,x).StartThreadProcess))).Start();
 
x.DownloadFile(F,@"E:temptemp" + f,a._K);
// x.DownloadFileChunk(F,15,34556);
 
System.Console.ReadLine();
// string uploadfile = "e:test_local.rar";
// string str = x.UploadFileEx("http://localhost/phpmyadmin/uploadaction.php",uploadfile,"file1");
// System.Console.WriteLine(str);
// System.Console.ReadLine();
}
 
string bs = ""; //用于记录上次的位数
bool b = false;
private int i = 0;
private static object _SyncLockObject = new object();
string _F;
string _f;
 
private void x_DataReceive(Microshaoft.Utils.HttpWebClient Sender,Microshaoft.Utils.DownLoadEventArgs e)
{
if (!this.b)
{
lock (_SyncLockObject)
{
if (!this.b)
{
System.Console.Write(System.DateTime.Now.ToString() + " 已接收数据: ");
//System.Console.Write( System.DateTime.Now.ToString() + " 已接收数据: ");
this.b = true;
}
}
}
string f = e.DownloadState.FileName;
if (e.DownloadState.AttachmentName != null)
f = System.IO.Path.GetDirectoryName(f) + @"" + e.DownloadState.AttachmentName;
 
this._f = f;
 
using (System.IO.FileStream sw = new System.IO.FileStream(f,System.IO.FileMode.OpenOrCreate,System.IO.FileAccess.ReadWrite,System.IO.FileShare.ReadWrite))
{
sw.Position = e.DownloadState.Position;
sw.Write(e.DownloadState.Data,e.DownloadState.Data.Length);
sw.Close();
}
string s = System.DateTime.Now.ToString();
lock (_SyncLockObject)
{
this.i += e.DownloadState.Data.Length;
System.Console.Write(bs + "bbbbbbbbbb" + i + " / " + Sender.FileLength + " 字节数据 " + s);
//System.Console.Write(bs + i + " 字节数据 " + s);
this.bs = new string('b',Digits(i) + 3 + Digits(Sender.FileLength) + s.Length);
}
}
 
int Digits(int n) //数字所占位数
{
n = System.Math.Abs(n);
n = n / 10;
int i = 1;
while (n > 0)
{
n = n / 10;
i++;
}
return i;
}
 
private void x_ExceptionOccurrs(Microshaoft.Utils.HttpWebClient Sender,Microshaoft.Utils.ExceptionEventArgs e)
{
System.Console.WriteLine(e.Exception.Message);
//发生异常重新下载相当于断点续传,你可以自己自行选择处理方式
Microshaoft.Utils.HttpWebClient x = new Microshaoft.Utils.HttpWebClient();
x.DownloadFileChunk(this._F,this._f,e.DownloadState.Position,e.DownloadState.Length);
e.ExceptionAction = Microshaoft.Utils.ExceptionActions.Ignore;
}
 
private void x_ThreadProcessEnd(Microshaoft.Utils.HttpWebClient Sender,Microshaoft.Utils.ThreadProcessEventArgs e)
{
//if (e.thread.ThreadState == System.Threading.ThreadState.Stopped)
if (this._k ++ == this._K - 1)
System.Console.WriteLine("nend");
}
}