文件上传到FTP服务器 [英] File Upload to FTP server

问题描述

将文件上传到ftp服务器时出现异常。我正在执行以下代码并获取''System.Net.FtpWebRequest'的类型初始化程序引发异常。

  private   FtpWebRequest   ftpRequest   =  null; 
  private   Stream   ftpStream  < span class =code-leadattribute> =  null; 
  private   int   bufferSize  < span class =code-leadattribute> =  2048; 

  protected   void  btnSubmit_Click（ object  sender，EventArgs e）
 {
  byte  [] byteBuffer =  new  字节 [BUFFERSIZE]; 
  byte  [] Data = fileArray.FileBytes; 
 TransferFile（fileArray.PostedFile.FileName，Data））; 
} 

  public   string  TransferFile（ string  filename， byte  [] fileContent）
 {
 
 
  string  strMsg = 串 .Empty; 
 尝试 
 {
 
  / *  创建FTP请求* /  
 字符串 uploadUrl = 字符串 .Format（  {0} / {1} / {2}，< span class =code-string>  ftp：// address，  foldername，filename）; 
 ftpRequest =（FtpWebRequest）FtpWebRequest.Create（ new  Uri（uploadUrl））; 
  / *  使用提供的用户名和密码登录FTP服务器* /  
 ftpRequest.Credentials =  new  NetworkCredential（ 用户名， 密码）; 
  / *  如有疑问，请使用以下选项* /  
 ftpRequest.UseBinary =  true ; 
 ftpRequest.UsePassive =  true ; 
 ftpRequest.KeepAlive =  true ; 
  / *  指定FTP请求的类型* /  
 ftpRequest.Method = WebRequestMethods.Ftp.UploadFile; 
 
 ftpStream = ftpRequest.GetRequestStream（）; 
 
 
  / *  通过发送缓冲数据上传文件，直到传输为止完成* /  
 尝试 
 {
 
 ftpRequest.ContentLength = fileContent.Length; 
 
流requestStream = ftpRequest.GetRequestStream（）; 
 requestStream.Write（fileContent， 0 ，fileContent.Length）; 
 requestStream.Close（）; 
 
 FtpWebResponse response =（FtpWebResponse）ftpRequest.GetResponse（）; 
 strMsg =  文件上传状态： + response.ToString（）; 
 
} 
  catch （Exception ex）{Console.WriteLine（ex.ToString（））; } 
  / *  资源清理* /  
 ftpStream.Close（）; 
 ftpRequest =  null ; 
} 
  catch （Exception ex）{Console.WriteLine（ex.ToString（））; } 
  return  strMsg; 
 
} 

如果我做错了请建议。

解决方案

您需要增加 FtpWebRequest.Timeout属性 [ ^ ]。



参考 - 底层连接是已关闭：接收时发生意外错误 [ ^ ]。

引用：

只是想加强ScottE的诊断，并且更加具体。超时很可能是问题。



FtpWebRequest的.Net实现是错误的还是 MSDN文档有拼写错误，FtpWebRequest.Timeout的默认值不是-1（无限）。它是100000（100秒）。



此外还有另一个超时问题。一些测试表明，responseStream的超时值总是为300000（300秒）。我不知道如何分配这个值。无论如何，需要修改此值以适应大文件。



总之，解决方案是将FtpWebRequest.Timeout和Stream.Timeout设置为足够大的值

I got exception while upload file to ftp server. I am doing following code and get The type initializer for ''System.Net.FtpWebRequest'' threw an exception.

private FtpWebRequest ftpRequest = null;
            private Stream ftpStream = null;
            private int bufferSize = 2048;

protected void btnSubmit_Click(object sender, EventArgs e)
        {            
            byte[] byteBuffer = new byte[bufferSize];
            byte[] Data = fileArray.FileBytes;
           TransferFile(fileArray.PostedFile.FileName, Data));
        }

public string TransferFile(string filename, byte[] fileContent)
        {
            

            string strMsg = string.Empty;
            try
            {

                /* Create an FTP Request */
                String uploadUrl = String.Format("{0}/{1}/{2}", "ftp://address", "foldername", filename);
                ftpRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri(uploadUrl));
                /* Log in to the FTP Server with the User Name and Password Provided */
                ftpRequest.Credentials = new NetworkCredential("Username", "Password");
                /* When in doubt, use these options */
                ftpRequest.UseBinary = true;
                ftpRequest.UsePassive = true;
                ftpRequest.KeepAlive = true;
                /* Specify the Type of FTP Request */
                ftpRequest.Method = WebRequestMethods.Ftp.UploadFile;
                
                ftpStream = ftpRequest.GetRequestStream();                

                
                /* Upload the File by Sending the Buffered Data Until the Transfer is Complete */
                try
                {
                    
                    ftpRequest.ContentLength = fileContent.Length;

                    Stream requestStream = ftpRequest.GetRequestStream();
                    requestStream.Write(fileContent, 0, fileContent.Length);
                    requestStream.Close();
                    
                    FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse();
                    strMsg = "File Upload Status: " + response.ToString();

                }
                catch (Exception ex) { Console.WriteLine(ex.ToString()); }
                /* Resource Cleanup */
                ftpStream.Close();
                ftpRequest = null;
            }
            catch (Exception ex) { Console.WriteLine(ex.ToString()); }
            return strMsg;

        }

Please suggest if I do wrong.

解决方案

You need to increase the FtpWebRequest.Timeout Property [^].

Refer - The underlying connection was closed: An unexpected error occurred on a receive[^].

Quote:

Just want to strengthen ScottE''s diagnosis, and be more specific. Timeout is most likely the issue.

Either .Net implementation of FtpWebRequest is erroneous or the MSDN document has a typo, the default value of FtpWebRequest.Timeout is not -1 (Infinite). It is 100000 (100 seconds).

In addition there is another timeout issue. A few tests have shown that responseStream always has a timeout value of 300000 (300 seconds). I do not how this value is assigned. Anyways, this value needs to be modified to accommodate large files.

In summary, the solution is to set FtpWebRequest.Timeout and Stream.Timeout to a sufficiently large value

.

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