大文件下载问题(解决安全,速度,断点续传,多线程下载,服务器高占有问题)

namespace DownFile

{

using System;

using System.Web;

using System.Net;

using System.IO;

using System.Text;

using System.Data;

using System.Data.SqlClient;

* 1.支持断点续传

* 2.支持多线程下载

* 3.解决速度问题

* 4.文件播放解决拖动问题

* 5.解决服务器资源高占有问题

/// <summary>

/// DownFile 的摘要说明。

/// </summary>

public class GetFile : System.Web.UI.Page

{

* 支持断点续传

* 解决速度问题

* 支持大文件

private string file ;

private string fileHead ;

private string sqlConnString ;

public string SqlConnString{

get{

if(sqlConnString==null)

sqlConnString = System.Configuration.ConfigurationSettings.AppSettings["SqlConnString"];

return sqlConnString;

}

private string headFilePath;

public string HeadFilePath{

get{

if(headFilePath==null)

headFilePath = System.Configuration.ConfigurationSettings.AppSettings["HeadFilePath"];

return headFilePath;

}

private void Login(){

// 从IChannal中捕获UserName 和 PassWord;

// <add key="LoginUrl" value="Http://192.168.2.89/yu.php?Require=name=111@111.com&pass=111111" />

string loginUrl = System.Configuration.ConfigurationSettings.AppSettings["LoginUrl"];

//"asdfffgsdf-=-sd09-593%@#42593049523-4"

//loginUrl += "name=111@111.com&pass=111111";

string userInfo = Request.Headers["UserInfo"];

if(userInfo == null){

// 用户没有登陆验证

// Response.Write("用户没有登陆!");

Response.StatusDescription = "用户没有登陆!";

ResponseEnd(407);

}

loginUrl += userInfo;

//利用 WebClient 取得远程登陆校验得结果

WebClient wc = new WebClient();

wc.Credentials = CredentialCache.DefaultCredentials;

try{

byte[] loginData = wc.DownloadData(loginUrl);

string loginResult = Encoding.Default.GetString(loginData);

//1 登陆成功 0 登陆失败 2 没有该用户名

if(System.Convert.ToInt32(loginResult) == 1)

return;

else if(System.Convert.ToInt32(loginResult) == 0){

//用户登陆校验失败

//Response.Write("用户登陆校验失败!");

Response.StatusDescription = "登陆失败!";

ResponseEnd(418);

}

else{ //(System.Convert.ToInt32(loginResult) == 2){

//Response.Write("不存在改用户名!");

Response.StatusDescription = "登陆失败!";

ResponseEnd(419);

}

catch(Exception){

//不能访问Url登陆,登陆结果异常,登陆失败

Response.StatusDescription = "不能访问Url登陆,登陆结果异常,登陆失败!";

ResponseEnd(420);

}

private void Permit(){

string cGuid = Request.QueryString["cguid"];

string fileName = Request.QueryString["f"];

if(cGuid == null || fileName == null){

Response.StatusDescription = "参数错误.";

ResponseEnd(412);

}

SqlConnection sqlConn = new SqlConnection(SqlConnString);

sqlConn.Open();

//校验下载次数

string sql ;

SqlCommand sqlCmd = new SqlCommand();

sqlCmd.CommandType = CommandType.Text;

sqlCmd.Connection = sqlConn;

sql = @"Select Retailers.RetailerUid From Retailers Inner Join LimitDownLoad on LimitDownLoad.RetailerId = Retailers.Id

Where LimitDownLoad.RetailerId = (Select RetailerId From LimitDownLoad Where ContentGuid=@ContentGuid)

Group By Retailers.LimitDown,Retailers.RetailerUid

Having Sum(LimitDownLoad.DownCount)<Retailers.LimitDown";

sqlCmd.CommandText = sql;

sqlCmd.Parameters.Add("@ContentGuid",SqlDbType.VarChar,36);

sqlCmd.Parameters["@ContentGuid"].Value = cGuid;

Object objDown = sqlCmd.ExecuteScalar();

if(objDown == null){

//校验失败,或没有经过下载预置(LimitDownLoad)

Response.StatusDescription = "校验失败,或没有经过下载预置(LimitDownLoad).";

sqlConn.Close();

ResponseEnd(402);

}

string rGuid = objDown.ToString();

//查找文件

sql = @"Select OutputFile+\'\\'+FileName As FileName From WaitPack Inner join LimitDownLoad On LimitDownLoad.ContentId=WaitPack.ContentId Where IsPacking=3 And LimitDownLoad.ContentGuid=@ContentGuid And FileName=@FileName";

sqlCmd.CommandText = sql;

sqlCmd.Parameters.Clear();

sqlCmd.Parameters.Add("@ContentGuid",SqlDbType.VarChar,36);

sqlCmd.Parameters["@ContentGuid"].Value = cGuid;

sqlCmd.Parameters.Add("@FileName",SqlDbType.VarChar,100);

sqlCmd.Parameters["@FileName"].Value = fileName;

Object objFile = sqlCmd.ExecuteScalar();

if(objFile == null){

//数据库中不存在改打包文件,即该文件没有被打包

Response.StatusDescription = "数据库中不存在改打包文件.";

sqlConn.Close();

ResponseEnd(404);

}

//从数据库中取得文件的绝对物理路径

file = objFile.ToString();

//处理file中 \\192.168.2.3\\001.wmv => \\192.168.2.3\001.wmv 两者相等的

file = file.Replace(@"\\",@"\");

file = @"\"+file;

//--------end

fileHead = HeadFilePath+rGuid+@"\"+GetHeadFile(file);

fileHead = fileHead.Replace(@"\\",@"\");

//fileHead = @"\"+fileHead;

if(!File.Exists(file) || !File.Exists(fileHead)){

//文件或头文件不存在!

Response.StatusDescription = "文件或头文件不存在!";//或者是没有访问文件的权限

sqlConn.Close();

ResponseEnd(404);

}

//更新下载次数

* 这部分 IChannal 那边下载完后处理

sql = "Update LimitDownLoad Set DownCount=DownCount+1 Where ContentGuid=@ContentGuid";

sqlCmd.CommandText = sql;

sqlCmd.Parameters.Clear();

sqlCmd.Parameters.Add("@ContentGuid",SqlDbType.VarChar,36);

sqlCmd.Parameters["@ContentGuid"].Value = cGuid;

sqlCmd.ExecuteNonQuery();

sqlConn.Close();

}

private void ResponseEnd(int statusCode){

Response.StatusCode = statusCode;

Response.End();

}

private string GetHeadFile(string file){

string f1 = Path.GetFileNameWithoutExtension(file);

string f2 = Path.GetExtension(file);

return f1+"_h"+f2;

}

private string GetMime(string fileName){

string fileExtent = Path.GetExtension(fileName);

//int index = fileName.LastIndexOf(\'.\');

//fileName.Substring(index,fileName.Length-index-1);

string retMime;

switch(fileExtent){

case ".rm":

retMime = "application/vnd.rn-realmedia";

break;

case ".mp3":

retMime = "application/mp3";

break;

case ".asf":

retMime = "video/x-ms-asf";

break;

case ".avi":

retMime = "video/avi";

break;

case ".wav":

retMime = "audio/wav";

break;

case ".wmv":

retMime = "audio/wmv";

break;

case ".mpg":

retMime = "video/mpeg";

break;

case ".mpeg":

retMime = "video/mpeg";

break;

default:

retMime = "application/octet-stream";

break;

}

return retMime;

}

protected override void OnInit(EventArgs e)

{

//登陆校验

//过滤限制条件

Permit();

//file = @"C:\xx.wmv";

//fileHead = @"C:\xx_h.wmv";

//文件以共享方式打开

FileStream fs = new FileStream(file,FileMode.Open,FileAccess.Read,FileShare.Read);

Response.Clear();

Response.ContentType = GetMime(file);

//Range: bytes=449794- || bytes=449794-588888

FileStream fsHead = new FileStream(fileHead,FileMode.Open,FileAccess.Read,FileShare.Read);

byte[] buff = new byte[209152] ;

//文件长度,每个不同offset请求时,抛出给客户端的文件大小随之变化

long length = fs.Length-10240+fsHead.Length;

//得到客户端请求文件定位位置

string Range = Request.Headers["Range"];

//默认起始位置是文件开头,结尾位置是文件结尾

//去掉文件的头10K 大小!

long offset=0,endset = fs.Length-10240+fsHead.Length;

int len; //实际读的文件的字节数

Response.AppendHeader("Content-Disposition","attachment;filename=" +Path.GetFileName(file));

Response.Buffer = true;

Response.StatusCode = 200;

if(Range != null && Range != ""){

Response.StatusCode = 206;

int index = Range.IndexOf(\'=\');

Range = Range.Substring(index+1,Range.Length-index-1);

index = Range.IndexOf(\'-\');

//取得文件的开始和结尾的文件位置

offset = System.Convert.ToInt32(Range.Substring(0,index));

//if(index < Range.Length-1)

//endset = System.Convert.ToInt32(Range.Substring(index+1,Range.Length-index-1));

length = endset - offset ;

//文件定位

//fs.Seek(offset,SeekOrigin.Begin);

}

Response.AppendHeader("Content-Length",length.ToString());

//仅仅定位到头文件中!

//抛出头文件中的类容

if(offset < fsHead.Length) {

//头最大为10K左右默认读取设置100k

fsHead.Seek(offset,SeekOrigin.Begin);

len = fsHead.Read(buff,0,102400);

Response.OutputStream.Write(buff,0,len);

Response.Flush();

fs.Seek(10240,SeekOrigin.Begin);

}

else{

//设置默认定位

fs.Seek(offset-fsHead.Length+10240,SeekOrigin.Begin);

}

//每次读取1M的类容

len = fs.Read(buff,0,209152);//104576 2M

while(len > 0 ) {

if (Response.IsClientConnected) {

Response.OutputStream.Write(buff,0,len);

Response.Flush();

len = fs.Read(buff,0,209152);//1048576

}

else {

len = 0;

}

fs.Close();

fsHead.Close();

Response.End();

}

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大文件下载问题(解决安全,速度,断点续传,多线程下载,服务器高占有问题)

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