/* .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 ,重载或增加了若干: * 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! * * 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! * */ 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;
//
internal void StartDownloadFileChunk() { if (this._ThreadCallback != null) { this._ThreadCallback(this._RequestURL, this._FileName, this._Position, this._Length); } }}
//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; }}
/// <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
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, new ThreadCallbackHandler(this.DownloadFileChunk)); // 单线程下载 // x.StartDownloadFileChunk();//多线程下载
//Thread t = new Thread(new ThreadStart(x.StartDownloadFileChunk)).Start(); //t.Start(); } p += s; } s = ss; byte[] buffer = this.ResponseAsBytes(Address, hwrp, s, 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, 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; } }}
/// <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, 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, 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(buffer1, p, buffer, 0, buffer.Length); DownLoadState dls = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, 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, 0, buffer3, 0, num3); buffer1 = buffer3; } return buffer1; } catch (Exception e) { ExceptionActions ea = ExceptionActions.Throw; if (this.ExceptionOccurrs != null) { DownLoadState x = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, P, num2); 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; } 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, fileName, fieldName)); }public byte[] UploadFile(string address, string method, string fileName, 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, "\r\nContent-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"", Path.GetFileName(fileName), "\"\r\nContent-Type: ", text2, "\r\n\r\n" }; string text3 = string.Concat(textArray1); byte[] buffer1 = Encoding.UTF8.GetBytes(text3); byte[] buffer2 = Encoding.ASCII.GetBytes("\r\n--" + text1 + "\r\n"); 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, 0, buffer1.Length); do { num2 = stream1.Read(buffer3, 0, buffer3.Length); if (num2 != 0) { stream2.Write(buffer3, 0, num2); } } while (num2 != 0); stream2.Write(buffer2, 0, 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, 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; } } while (num2 != 0); stream1.Close(); if (flag1) { byte[] buffer3 = new byte[num3]; Buffer.BlockCopy(buffer1, 0, buffer3, 0, 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; }}
}