I need to stream a file which will result in save as prompt in the browser.
The issue is, the directory that the file is located is virtually mapped, so I am unable to use Server.MapPath to determine it's actual location. The directory is not in the same location (or even phyical server on the live boxes) as the website.
I'd like something like the following, but that will allow me to pass a web URL, and not a server file path.
I may have to end up building my file path from a config base path, and then append on the rest of the path, but hopefully I can do it this way instead.
var filePath = Server.MapPath(DOCUMENT_PATH);
if (!File.Exists(filePath))
return;
var fileInfo = new System.IO.FileInfo(filePath);
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", String.Format("attachment;filename=\"{0}\"", filePath));
Response.AddHeader("Content-Length", fileInfo.Length.ToString());
Response.WriteFile(filePath);
Response.End();
You could use HttpWebRequest to get the file and stream it back to the client. This allows you to get the file with a url. An example of this that I found ( but can't remember where to give credit ) is
//Create a stream for the file
Stream stream = null;
//This controls how many bytes to read at a time and send to the client
int bytesToRead = 10000;
// Buffer to read bytes in chunk size specified above
byte[] buffer = new Byte[bytesToRead];
// The number of bytes read
try
{
//Create a WebRequest to get the file
HttpWebRequest fileReq = (HttpWebRequest) HttpWebRequest.Create(url);
//Create a response for this request
HttpWebResponse fileResp = (HttpWebResponse) fileReq.GetResponse();
if (fileReq.ContentLength > 0)
fileResp.ContentLength = fileReq.ContentLength;
//Get the Stream returned from the response
stream = fileResp.GetResponseStream();
// prepare the response to the client. resp is the client Response
var resp = HttpContext.Current.Response;
//Indicate the type of data being sent
resp.ContentType = MediaTypeNames.Application.Octet;
//Name the file
resp.AddHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
resp.AddHeader("Content-Length", fileResp.ContentLength.ToString());
int length;
do
{
// Verify that the client is connected.
if (resp.IsClientConnected)
{
// Read data into the buffer.
length = stream.Read(buffer, 0, bytesToRead);
// and write it out to the response's output stream
resp.OutputStream.Write(buffer, 0, length);
// Flush the data
resp.Flush();
//Clear the buffer
buffer = new Byte[bytesToRead];
}
else
{
// cancel the download if client has disconnected
length = -1;
}
} while (length > 0); //Repeat until no data is read
}
finally
{
if (stream != null)
{
//Close the input stream
stream.Close();
}
}
Download url to bytes and convert bytes into stream:
using (var client = new WebClient())
{
var content = client.DownloadData(url);
using (var stream = new MemoryStream(content))
{
...
}
}
I do this quite a bit and thought I could add a simpler answer. I set it up as a simple class here, but I run this every evening to collect financial data on companies I'm following.
class WebPage
{
public static string Get(string uri)
{
string results = "N/A";
try
{
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(uri);
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
StreamReader sr = new StreamReader(resp.GetResponseStream());
results = sr.ReadToEnd();
sr.Close();
}
catch (Exception ex)
{
results = ex.Message;
}
return results;
}
}
In this case I pass in a url and it returns the page as HTML. If you want to do something different with the stream instead you can easily change this.
You use it like this:
string page = WebPage.Get("http://finance.yahoo.com/q?s=yhoo");
2 years later, I used Dallas' answer, but I had to change the HttpWebRequest to FileWebRequest since I was linking to direct files. Not sure if this is the case everywhere, but I figured I'd add it. Also, I removed
var resp = Http.Current.Resonse
and just used Http.Current.Response in place wherever resp was referenced.
If you are looking for a .NET Core version of #Dallas's answer, use the below.
Stream stream = null;
//This controls how many bytes to read at a time and send to the client
int bytesToRead = 10000;
// Buffer to read bytes in chunk size specified above
byte[] buffer = new Byte[bytesToRead];
// The number of bytes read
try
{
//Create a WebRequest to get the file
HttpWebRequest fileReq = (HttpWebRequest)HttpWebRequest.Create(#"file url");
//Create a response for this request
HttpWebResponse fileResp = (HttpWebResponse)fileReq.GetResponse();
if (fileReq.ContentLength > 0)
fileResp.ContentLength = fileReq.ContentLength;
//Get the Stream returned from the response
stream = fileResp.GetResponseStream();
// prepare the response to the client. resp is the client Response
var resp = HttpContext.Response;
//Indicate the type of data being sent
resp.ContentType = "application/octet-stream";
//Name the file
resp.Headers.Add("Content-Disposition", "attachment; filename=test.zip");
resp.Headers.Add("Content-Length", fileResp.ContentLength.ToString());
int length;
do
{
// Verify that the client is connected.
if (!HttpContext.RequestAborted.IsCancellationRequested)
{
// Read data into the buffer.
length = stream.Read(buffer, 0, bytesToRead);
// and write it out to the response's output stream
resp.Body.Write(buffer, 0, length);
//Clear the buffer
buffer = new Byte[bytesToRead];
}
else
{
// cancel the download if client has disconnected
length = -1;
}
} while (length > 0); //Repeat until no data is read
}
finally
{
if (stream != null)
{
//Close the input stream
stream.Close();
}
}
I would argue the simplest way to do so in .Net Core is:
using (MemoryStream ms = new MemoryStream())
using (HttpClient client = new HttpClient())
{
client.GetStreamAsync(url).Result.CopyTo(ms);
// use ms in what you want
}
}
now you have the file downloaded as stream inside ms.
You could try using the DirectoryEntry class with the IIS path prefix:
using(DirectoryEntry de = new DirectoryEntry("IIS://Localhost/w3svc/1/root" + DOCUMENT_PATH))
{
filePath = de.Properties["Path"].Value;
}
if (!File.Exists(filePath))
return;
var fileInfo = new System.IO.FileInfo(filePath);
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", String.Format("attachment;filename=\"{0}\"", filePath));
Response.AddHeader("Content-Length", fileInfo.Length.ToString());
Response.WriteFile(filePath);
Response.End();
The accepted solution from Dallas was working for us if we use Load Balancer on the Citrix Netscaler (without WAF policy).
The download of the file doesn't work through the LB of the Netscaler when it is associated with WAF as the current scenario (Content-length not being correct) is a RFC violation and AppFW resets the connection, which doesn't happen when WAF policy is not associated.
So what was missing was:
Response.End();
See also:
Trying to stream a PDF file with asp.net is producing a "damaged file"
Related
I am using mvc I am trying to save a file on another folder i.e on another server.
But earlier i was using an approach of creating two different solution and was saving the file using web request.
i was sending the request from one solution and was geeting it on another solution.
here is my code
byte[] bytes;
var pic = System.Web.HttpContext.Current.Request.Files["ImagePath"];
/*Creating the WebRequest object using the URL of SaveFile.aspx.*/
System.Net.HttpWebRequest webRequest =
(System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create
("http://localhost:13492/Home/SaveImage");
webRequest.Method = "POST";
webRequest.KeepAlive = false;
/*Assigning the content type from the FileUpload control.*/
webRequest.ContentType = pic.ContentType ;
/*Creating the Header object.*/
System.Net.WebHeaderCollection headers = new System.Net.WebHeaderCollection();
headers.Add("FileName", pic.FileName);
/*Adding the header to the WebRequest object.*/
webRequest.Headers = headers;
/* Convert File Into byte array */
using (var stream = new MemoryStream())
{
pic.InputStream.CopyTo(stream);
bytes = stream.ToArray();
}
/*Getting the request stream by making use of the GetRequestStream method of WebRequest object.*/
using (System.IO.Stream stream = webRequest.GetRequestStream())//Filling request stream with image stream.
{
/*Writing the FileUpload content to the request stream.*/
stream.Write(bytes, 0, pic.ContentLength);
}
/*Creating a WebResponse object by calling the GetResponse method of WebRequest object.*/
using (System.Net.HttpWebResponse webResponse = (System.Net.HttpWebResponse)webRequest.GetResponse())
{
/*Retrieving the response stream from the WebResponse object by calling the GetResponseStream method.*/
using (System.IO.StreamReader sr = new System.IO.StreamReader(webResponse.GetResponseStream()))
{
string path = sr.ReadToEnd();
}
}
then in another solution i was getting it to save the file.
public void SaveImage()
{
try
{
/*Retrieving the file name from the headers in the request. */
string destinationFileName = Path.Combine(#"~/" + "Portfolio" + "/", Request.Headers["FileName"].ToString());
string fileName = System.Web.HttpContext.Current.Server.MapPath(destinationFileName);
//string path = System.IO.Path.Combine(Server.MapPath("."), Request.Headers["FileName"].ToString());
using (System.IO.FileStream fileStream = System.IO.File.Create(fileName))
{
/*Getting stream from the Request object.*/
using (System.IO.Stream stream = Request.InputStream)
{
int byteStreamLength = (int)stream.Length;
byte[] byteStream = new byte[byteStreamLength];
/*Reading the stream to a byte array.*/
stream.Read(byteStream, 0, byteStreamLength);
/*Writing the byte array to the harddisk.*/
fileStream.Write(byteStream, 0, byteStreamLength);
}
}
Response.Clear();
/*Writing the status to the response.*/
Response.Write(fileName);
}
catch (Exception ex)
{
/*Writing the error message to the response stream.*/
Response.Clear();
Response.Write("Error: " + ex.Message);
}
}
So what should i change in code so that i could save the file on another location on another server without writing the code on two different place.
I've got a solution for this problem and its working fine.
public static void UploadFtpFile(string folderName, string fileName)
{
FtpWebRequest request;
try
{
//string folderName;
//string fileName;
string absoluteFileName = Path.GetFileName(fileName);
request = WebRequest.Create(new Uri(string.Format(#"ftp://{0}/{1}/{2}", "ftp.site4now.net", folderName, absoluteFileName))) as FtpWebRequest;
request.Method = WebRequestMethods.Ftp.UploadFile;
request.UseBinary = true;
request.UsePassive = true;
request.KeepAlive = true;
request.Credentials = new NetworkCredential("Username", "Password");
request.ConnectionGroupName = "group";
using (FileStream fs = System.IO.File.OpenRead(fileName))
{
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
fs.Close();
Stream requestStream = request.GetRequestStream();
requestStream.Write(buffer, 0, buffer.Length);
requestStream.Flush();
requestStream.Close();
}
}
catch (Exception ex)
{
}
}
Follow Below Sample
This sample is for creating a folder on another server over FTP protocol. Please extend it as per need.
using System;
using System.Net;
class Test
{
static void Main()
{
WebRequest request = WebRequest.Create("ftp://host.com/directory");
request.Method = WebRequestMethods.Ftp.MakeDirectory;
request.Credentials = new NetworkCredential("user", "pass");
using (var resp = (FtpWebResponse) request.GetResponse())
{
Console.WriteLine(resp.StatusCode);
}
}
}
As per the comment by #ADyson you must enable the FTP Protocol before working using this sample
I'm trying create a small http proxy service. This is not working so well. It is able to serve HTML okayish, however it chokes up on images. That is, some images.
Sending in a url through my proxy yields 19.4 kb in the response (according to firebug)
Visiting that url directly also yields 19.4 kb in the response, again according to firebug. The difference is, it doesn't show up when I put it through my proxy, but it does when I browse directly.
A completely different url works just fine. Does anyone have any idea?
private void DoProxy()
{
var http = listener.GetContext();
string url = http.Request.QueryString["url"];
WebRequest request = HttpWebRequest.Create(url);
WebResponse response = request.GetResponse();
http.Response.ContentType = response.ContentType;
byte[] content;
using (Stream responseStream = response.GetResponseStream())
content = ReadAll(responseStream);
http.Response.ContentLength64 = content.Length;
http.Response.OutputStream.Write(content, 0, content.Length);
http.Response.Close();
}
private byte[] ReadAll(Stream stream)
{
IList<byte> array = new List<byte>();
int b;
while ((b = stream.ReadByte()) != -1)
array.Add(Convert.ToByte(b));
return array.ToArray();
}
I would try and flush/close the OutputStream before you close the response.
Also as a second suggestion have a look at the HTTP traffic from the original site and then through your proxy site using an HTTP debugger like Fiddler - there must be a difference when using your proxy.
Also to make the ReadAll method more effective, in general I would avoid to load the full content into memory, because this will blow up on huge files - just stream them directly from the input stream to the output stream. If you still want to use byte arrays consider the following (untested but should work):
private byte[] ReadAll(Stream stream)
{
byte[] buffer = new byte[8192];
int bytesRead = 1;
List<byte> arrayList = new List<byte>();
while (bytesRead > 0)
{
bytesRead = stream.Read(buffer, 0, buffer.Length);
arrayList.AddRange(new ArraySegment<byte>(buffer, 0, bytesRead).Array);
}
return arrayList.ToArray();
}
You can try to replace
http.Response.Close();
with
http.Response.Flush();
http.Response.End();
A problem could be that you don't specify the MIME type of the response. Browsersthese days are very forgiving, but maybe there is a circumstance where the browser doesn't know how to handle whatever you are sticking through its throat.
I have written the most smallish file-based http server, presented here, which as far as I can remember can serve images without much problem.
Just separate the text response and image response, and write the outputs separately. I did like below and it worked for me.
static void Main(string[] args)
{
HttpListener server = new HttpListener();
server.Prefixes.Add("http://localhost:9020/");
server.Start();
Console.WriteLine("Listening...");
while (true)
{
try
{
HttpListenerContext context = server.GetContext();
HttpListenerResponse response = context.Response;
String localpath = context.Request.Url.LocalPath;
string page = Directory.GetCurrentDirectory() + localpath;
string msg = "";
bool imgtest = false;
if (localpath == "/")
page = "index.html";
Console.WriteLine(localpath);
if (!page.Contains("jpg") && !page.Contains("png"))//Separates image request
{
TextReader tr = new StreamReader(page);
msg = tr.ReadToEnd();
tr.Dispose();
}
else
{
byte[] output = File.ReadAllBytes(page);
response.ContentLength64 = output.Length;
Stream st1 = response.OutputStream;
st1.Write(output, 0, output.Length);
imgtest = true;
}
if (imgtest==false)
{
byte[] buffer = Encoding.UTF8.GetBytes(msg);
response.ContentLength64 = buffer.Length;
Stream st = response.OutputStream;
st.Write(buffer, 0, buffer.Length);
context.Response.Close();
}
}
catch (Exception ex)
{
Console.WriteLine("Error: "+ex);
Console.ReadKey();
}
}
I am trying to use an FtpWebRequest to upload some files. This works for smallish files (say <2MB), but when I am trying to load a 16MB file, the files uploads successfully, but when I call request.GetRequestStream().Close, the code hangs (or timesout if the timeout is low enough).
I could just a) not close it and b)not bother to get the response from the server, but that doesn't seem right! See code below (using SSL or not, the same problem occurs.)
output.Close() is the line that hangs....
public static void SendFileViaFtp(string file, string url, bool useSsl, ICredentials credentials)
{
var request = (FtpWebRequest)WebRequest.Create(url + Path.GetFileName(file));
request.EnableSsl = useSsl;
request.UseBinary = true;
request.Credentials = credentials;
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Timeout = 10000000;
request.ReadWriteTimeout = 10000000;
request.KeepAlive = true;
var input = File.Open(file, FileMode.Open);
var output = request.GetRequestStream();
var buffer = new byte[1024];
var lastBytesRead = -1;
var i = 0;
while (lastBytesRead != 0)
{
i++;
lastBytesRead = input.Read(buffer, 0, 1024);
Debug.WriteLine(lastBytesRead + " " + i);
if (lastBytesRead > 0)
{
output.Write(buffer, 0, lastBytesRead);
}else
{
Debug.WriteLine("Finished");
}
}
input.Close();
output.Close();
var response = (FtpWebResponse)request.GetResponse();
response.Close();
}
Thanks,
try
// after finished uploading
request.Abort(); // <=== MAGIC PART
// befor response.Close()
var response = (FtpWebResponse)request.GetResponse();
response.Close();
taken from here
try to close output before input.
make sure the last buffer isn't to large, or you could write a few empty bytes.
I don't know if it's necessary but i always set the request contentlength to the inputfile-length.
Here is an good example: http://dotnet-snippets.de/dns/ftp-file-upload-mit-buffer-SID886.aspx
I am trying to write a proxy which reads an image from one server and returns it to the HttpContext supplied, but I am just getting character stream back.
I am trying the following:
WebRequest req = WebRequest.Create(image);
WebResponse resp = req.GetResponse();
Stream stream = resp.GetResponseStream();
StreamReader sr = new StreamReader(stream);
StreamWriter sw = new StreamWriter (context.Response.OutputStream);
sw.Write (sr.ReadToEnd());
But as I mentioned earlier, this is just responding with text.
How do I tell it that it is an image?
Edit: I am accessing this from within a web page in the source attribute of an img tag. Setting the content type to application/octet-stream prompts to save the file and setting it to image/jpeg just responds with the filename. What I want is the image to be returned and displayed by the calling page.
Since you are working with binary, you don't want to use StreamReader, which is a TextReader!
Now, assuming that you've set the content-type correctly, you should just use the response stream:
const int BUFFER_SIZE = 1024 * 1024;
var req = WebRequest.Create(imageUrl);
using (var resp = req.GetResponse())
{
using (var stream = resp.GetResponseStream())
{
var bytes = new byte[BUFFER_SIZE];
while (true)
{
var n = stream.Read(bytes, 0, BUFFER_SIZE);
if (n == 0)
{
break;
}
context.Response.OutputStream.Write(bytes, 0, n);
}
}
}
I guess you would need to check the ContentType returned by your WebResponse request.
if (resp.ContentType.StartsWith("image/"))
{
// Do your stuff
}
You're going to need to set the Content Type on your response. Here's a snippet of code that'll do it:
// specify that the response is a JPEG
// Also could use "image/GIF" or "image/PNG" depending on what you're
// getting from the server
Response.ContentType = "image/JPEG";
I use this in an application currently. Content URL is passed in as a query string value (the URL to the image).
try
{
if (ContentUrl != "")
{
string imgExtension = ContentUrl.Substring(ContentUrl.Length - 3, 3);
switch (imgExtension)
{
case "":
//image/bmp
Response.ContentType = "image/bmp";
break;
case "jpg":
//image/jpeg
Response.ContentType = "image/jpeg";
break;
case "gif":
//image/gif
Response.ContentType = "image/gif";
break;
default:
Response.ContentType = "image/jpeg";
break;
}
if (!ContentUrl.StartsWith("http"))
Response.BinaryWrite(new byte[] { 0 });
WebClient wc = new WebClient();
wc.Credentials = System.Net.CredentialCache.DefaultCredentials;
Byte[] result;
result = wc.DownloadData(ContentUrl);
Response.BinaryWrite(result);
}
}
catch (Exception ex)
{
Utility.WriteEventError(Utility.EVENTLOG_SOURCE, string.Format("ImageProxy Error... Url: {0}, Exception: {1}", ContentUrl, ex.ToString()));
}
finally
{
Response.End();
}
I have a sharepoint site that has an excel spreadsheet that I need to download on a schedulad basis
Is this possible?
Yes it is possible to download the file from sharepoint.
Once you have the url for the document, it can be downloaded using HttpWebRequest and HttpWebResponse.
attaching a sample code
DownLoadDocument(string strURL, string strFileName)
{
HttpWebRequest request;
HttpWebResponse response = null;
request = (HttpWebRequest)WebRequest.Create(strURL);
request.Credentials = System.Net.CredentialCache.DefaultCredentials;
request.Timeout = 10000;
request.AllowWriteStreamBuffering = false;
response = (HttpWebResponse)request.GetResponse();
Stream s = response.GetResponseStream();
// Write to disk
if (!Directory.Exists(myDownLoads))
{
Directory.CreateDirectory(myDownLoads);
}
string aFilePath = myDownLoads + "\\" + strFileName;
FileStream fs = new FileStream(aFilePath, FileMode.Create);
byte[] read = new byte[256];
int count = s.Read(read, 0, read.Length);
while (count > 0)
{
fs.Write(read, 0, count);
count = s.Read(read, 0, read.Length);
}
// Close everything
fs.Close();
s.Close();
response.Close();
}
You can also use the GetItem API of Copy service to download a file.
string aFileUrl = mySiteUrl + strFileName;
Copy aCopyService = new Copy();
aCopyService.UseDefaultCredentials = true;
byte[] aFileContents = null;
FieldInformation[] aFieldInfo;
aCopyService.GetItem(aFileUrl, out aFieldInfo, out aFileContents);
The file can be retrieved as a byte array.
You can also do this:
try
{
using (WebClient client = new WebClient())
{
client.Credentials = new NetworkCredential("username", "password", "DOMAIN");
client.DownloadFile(http_path, path);
}
}
catch (Exception ex)
{
MessageBox.Show("Error: " + ex.Message);
}
The link the to document in Sharepoint should be a static URL. Use that URL in whatever solution you have to grab the file on your schedule.
Why not just use wget.exe <url>. You can put that line in a batch file and run that through windows scheduler.