视频播放网站CDN内容分发网络简单代码实现

partial class FileDown : ServiceBase { //保存下载文件  Hashtable htDowFile = new Hashtable(); //下载文件数  int queueCount = Convert.ToInt32(ConfigurationManager.AppSettings["QueueCount"]); //当前下载文件数  int downCount = 0; public FileDown() { InitializeComponent(); } protected override void OnStart(string[] args) { // TODO: 在此处添加代码以启动服务。  fileDownTimer.Interval = 10000; fileDownTimer.Start(); //记录服务运行日志  Logger.LogDebug("FileDown", "OnStart", "文件下载服务开始运行。", null); } protected override void OnStop() { // TODO: 在此处添加代码以执行停止服务所需的关闭操作。  fileDownTimer.Stop(); //记录服务运行日志  Logger.LogDebug("FileDown", "OnStop", "文件下载服务停止运行。", null); } /// <summary> /// 时间控件处理事件 /// </summary> /// <param name="sender"></param> /// <param name="e"></param>  private void fileDownTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) { //记录文件下载日志  Logger.LogDebug("FileDown", "fileDownTimer_Elapsed", "开始一轮新的文件下载。", null); fileDownTimer.Stop(); WaitDownFileTxtManage myWaitDownFileXmlManage = new WaitDownFileTxtManage(); FileDownCommon myFileDownCommon = new FileDownCommon(); //从配置文件内获取txt文件路径  string txtPath = ConfigurationManager.AppSettings["txtPath"].ToString(); //循环下载所有文件  using (StreamReader sr = new StreamReader(txtPath)) { String line; while ((line = sr.ReadLine()) != null) { string[] fileElement = line.Split(';'); string downFileSavePath = fileElement[1] + ".downing"; if (!File.Exists(downFileSavePath)) { if (downCount <= queueCount) { downCount++; ThreadPool.QueueUserWorkItem(DownFile, line); } } } } //记录文件下载日志  Logger.LogDebug("FileDown", "fileDownTimer_Elapsed", "结束一轮新的文件下载。", null); Double interval = Convert.ToDouble(ConfigurationManager.AppSettings["Interval"].ToString()); fileDownTimer.Interval = interval * 60 * 1000; fileDownTimer.Start(); } /// <summary> /// 下载文件方法 /// </summary> /// <param name="downFile">下载文件</param>  private void DownFile(object downFile) { WaitDownFileTxtManage myWaitDownFileTxtManage = new WaitDownFileTxtManage(); string[] fileElement = downFile.ToString().Split(';'); string fileName = fileElement[0]; string downFileSavePath = fileElement[1] + ".downing"; string trueFilePath = fileElement[1]; string fileDownPath = fileElement[2]; string pathNoFile = downFileSavePath.Substring(0, downFileSavePath.LastIndexOf("\\")); //检查保存路径是否存在  if (!Directory.Exists(pathNoFile)) { Directory.CreateDirectory(pathNoFile); } //记录文件下载日志  Logger.LogDebug("FileDownCommon", "DownFile", "\"" + fileDownPath + "\"文件开始下载。", null); //打开上次下载的文件或新建文件  long lStartPos = 0; System.IO.FileStream fs; if (System.IO.File.Exists(downFileSavePath)) { fs = System.IO.File.OpenWrite(downFileSavePath); lStartPos = fs.Length; fs.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针  } else { fs = new System.IO.FileStream(downFileSavePath, System.IO.FileMode.Create); lStartPos = 0; } //打开网络连接  try { System.Net.WebRequest webRequest = System.Net.WebRequest.Create(fileDownPath); webRequest.Timeout = 10000; System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)webRequest; System.Net.HttpWebResponse response = (System.Net.HttpWebResponse)request.GetResponse(); //System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(fileDownPath); //请求正常  if (response.StatusCode == System.Net.HttpStatusCode.OK) { if (lStartPos > 0) request.AddRange((int)lStartPos); //设置Range值 //向服务器请求，获得服务器回应数据流  System.IO.Stream ns = response.GetResponseStream(); byte[] nbytes = new byte[10240]; int nReadSize = 0; nReadSize = ns.Read(nbytes, 0, 10240); while (nReadSize > 0) { fs.Write(nbytes, 0, nReadSize); nReadSize = ns.Read(nbytes, 0, 10240); } fs.Close(); ns.Close(); File.Move(downFileSavePath, trueFilePath); //删除下载完成的文件  myWaitDownFileTxtManage.DeleteDownFile(fileName, trueFilePath, fileDownPath); downCount--; //记录文件下载日志  Logger.LogDebug("FileDownCommon", "DownFile", "\"" + fileDownPath + "\"文件下载完成。", null); } //文件未找到  else if (response.StatusCode == System.Net.HttpStatusCode.NotFound) { //删除不存在的文件  myWaitDownFileTxtManage.DeleteDownFile(fileName, trueFilePath, fileDownPath); downCount--; fs.Close(); Logger.LogDebug("FileDownCommon", "DownFile", "\"" + fileDownPath + "\"文件在服务器上不存在。", null); } } catch (FileNotFoundException fileEx) { fs.Close(); downCount--; //删除不存在的文件  myWaitDownFileTxtManage.DeleteDownFile(fileName, trueFilePath, fileDownPath); //记录异常日志  Logger.LogError("FileDownCommon", "DownFile", AppError.EROR, 0, fileEx, "\"" + fileDownPath + "\"文件在服务器上不存在。", null); } catch (Exception ex) { fs.Close(); downCount--; //记录异常日志  Logger.LogError("FileDownCommon", "DownFile", AppError.EROR, 0, ex, "下载文件\"" + fileDownPath + "\"过程中出现错误：" + ex.ToString(), null); } } }