如何在FTP服务器上复制文件？

Question

如何在FTP服务器上复制文件？我的目标是将ftp://www.mysite.com/test.jpg复制到ftp://www.mysite.com/testcopy.jpg。如果要重命名文件，我会使用:

var request = (FtpWebRequest)WebRequest.Create("ftp://www.mysite.com/test.jpg");
request.Credentials = new NetworkCredential(user, pass);
request.Method = WebRequestMethods.Ftp.Rename;
request.RenameTo = "testrename.jpg"
request.GetResponse().Close();

FtpWebResponse resp = (FtpWebResponse)request.GetResponse();

然而，没有复制文件的方法。你该如何复制文件？

- msbg

---

你有其他访问服务器的方式吗？FTP 由于其名称的特性更适用于文件传输，而不是对这些文件进行远程管理。 - Joe

不，我实际上正在制作一个供任何人使用的FTP网页应用程序。 - msbg

那么你应该阅读RFC并了解协议实际上可以实现哪些功能。 - Joe

现在应该这么做。我暂时会下载并上传该文件，并用一个新的名称。 - msbg

Answer 1

试试这个：

static void Main(string[] args)
{
    CopyFile("countrylist.csv", "MySample.csv", "username", "password#");
}

public static bool CopyFile(string fileName, string FileToCopy, string userName, string password)
{
    try
    {
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://ftp.mysite.net/" + fileName);
        request.Method = WebRequestMethods.Ftp.DownloadFile;

        request.Credentials = new NetworkCredential(userName, password);
        FtpWebResponse response = (FtpWebResponse)request.GetResponse();
        Stream responseStream = response.GetResponseStream();
        Upload("ftp://ftp.mysite.net/" + FileToCopy, ToByteArray(responseStream), userName, password);
        responseStream.Close();
        return true;
    }
    catch
    {
        return false;
    }
}

public static Byte[] ToByteArray(Stream stream)
{
    MemoryStream ms = new MemoryStream();
    byte[] chunk = new byte[4096];
    int bytesRead;
    while ((bytesRead = stream.Read(chunk, 0, chunk.Length)) > 0)
    {
        ms.Write(chunk, 0, bytesRead);
    }

    return ms.ToArray();
}

public static bool Upload(string FileName, byte[] Image, string FtpUsername, string FtpPassword)
{
    try
    {
        System.Net.FtpWebRequest clsRequest = (System.Net.FtpWebRequest)System.Net.WebRequest.Create(FileName);
        clsRequest.Credentials = new System.Net.NetworkCredential(FtpUsername, FtpPassword);
        clsRequest.Method = System.Net.WebRequestMethods.Ftp.UploadFile;
        System.IO.Stream clsStream = clsRequest.GetRequestStream();
        clsStream.Write(Image, 0, Image.Length);

        clsStream.Close();
        clsStream.Dispose();
        return true;
    }
    catch
    {
        return false;
    }
}

这将文件下载到一个流中，然后上传它。

- Hanlet Escaño

---

我能从FTP服务器复制文件或上传到HTTP服务器吗？比如说，我想将ftp://ftpabcdef.com/abcdef.xml传输到http://xyzed.com/abcdef.xml。这段代码可以实现吗？还是需要编写其他内容？ - ratna

@ratna，你无法通过这段代码来完成目标任务。看起来询问一个新问题会更好。你需要通过FTP获取文件，在某个地方下载它（内存？），然后进行HTTP POST以将该文件上传到你的HTTP服务器上。 - Hanlet Escaño

感谢@HanletEscaño的回复。我之前问过这样的问题，但是被评为负分并最终关闭了。所以我必须将文件下载到本地机器，然后才能上传到http服务器？但是你能告诉我是否可以使用PowerShell或C#或任何其他语言从FTP传输文件到HTTP吗？我知道这是一个愚蠢的问题，但我还是问了因为我对此一无所知。 - ratna

Answer 2

FtpWebRequest是一个轻量级的类。Microsoft认为它应该被简单客户端用来在客户端完成后下载和删除文件。

- Black Frog

Answer 3

我猜你不能用FTP直接实现这个操作。你可以先下载想要复制的文件，然后用新的名称上传它。例如：

        try
        {
            WebClient request = new WebClient();
            request.Credentials = new NetworkCredential(user, pass);
            byte[] data = request.DownloadData(host);
            MemoryStream file = new MemoryStream(data);
            Upload(data);
        }
        catch (Exception ex)
        {

        }

    ...

    private void Upload(byte[] buffer)
    {
        try
        {
            FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(newname);

            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential(user, pass);

            Stream reqStream = request.GetRequestStream();
            reqStream.Write(buffer, 0, buffer.Length);
            reqStream.Close();

            var resp = (FtpWebResponse)request.GetResponse();
        }
        catch (Exception ex)
        {

        }
    }

- msbg

Answer 4

在我们的项目中，我们做了类似这样的事情。

// pass parameters according to your need, 
// the below code is done in a hard coded manner for clarity
public void Copy()  
{
    // from where you want to copy
    var downloadRequest = (FtpWebRequest)WebRequest.Create("ftp://www.mysite.com/test.jpg");
    downloadRequest.Credentials = new NetworkCredential("userName", "passWord");
    downloadRequest.Method = WebRequestMethods.Ftp.DownloadFile;

    var ftpWebResponse = (FtpWebResponse)downloadRequest.GetResponse();
    var downloadResponse = ftpWebResponse.GetResponseStream();

    int buffLength = 2048;
    byte[] byteBuffer = new byte[buffLength];

    // bytes read from download stream. 
    // from documentation: When overridden in a derived class, reads a sequence of bytes from the  
    // current stream and advances the position within the stream by the number of bytes read.
    int bytesRead = downloadResponse.Read(byteBuffer, 0, buffLength);

    // the place where you want the file to go
    var uploadRequest = (FtpWebRequest)WebRequest.Create("ftp://www.mysite.com/testCopy.jpg");
    uploadRequest.Credentials = new NetworkCredential("userName", "passWord");
    uploadRequest.Method = WebRequestMethods.Ftp.UploadFile;

    var uploadStream = uploadRequest.GetRequestStream();

    if (bytesRead > 0)
    {
        while (bytesRead > 0)
        {
            uploadStream.Write(byteBuffer, 0, bytesRead);
            bytesRead = downloadResponse.Read(byteBuffer, 0, buffLength);
        }
    }

    uploadStream.Close();
    uploadStream.Dispose();

    downloadResponse.Close();
    ftpWebResponse.Close();
    ((IDisposable)ftpWebResponse).Dispose();
}

- Yousuf Azad