asp.net mvc generate data to download file - c#

public ActionResult GetFile(string dateStr, string serverName, string foodName)
{
using (var memoStream = new MemoryStream(1024 * 5))
{
using (StreamWriter writer = new StreamWriter(memoStream))
{
var dataFilter = new CapacityDataFilter(dateStr, serverName, feedName);
dataFilter.FilterDataByServerAndFeed();
writer.WriteLine("Feed, StreamMin, TotalMsgNumber, TotalMsgSize, PeakRateMsgNumber, PeakRateMsgSize");
foreach (var element in dataFilter.DataInTheDay)
{
writer.WriteLine(string.Format("{0},{1},{2},{3},{4},{5}",
element.Feed, element.StreamMin,
element.TotalMsgNumber, element.TotalMsgSize,
element.PeakRateMsgNumber, element.PeakRateMsgSize));
}
return File(memoStream, "text/csv", fileName);
}
}
}
Exception Details: System.ObjectDisposedException: Cannot access a closed Stream.
this action doesn't work, how to make a download action?

"this action not work" is wrong way to explain problems...
But in this case you are lucky: you are trying to send incomplete data in memory stream that is seeked to the end, and as second issue stream will be disposed by the time File action actually executes.
The best fix is to move code outisde inner using and return new MemoryStream on buffer of old stream:
using (var memoStream = new MemoryStream(1024 * 5))
{
using (StreamWriter writer = new StreamWriter(memoStream))
{
...
}
return File(
new MemoryStream(memoStream.GetBuffer(), memoStream.length),
"text/csv", fileName);
}
Flush + Seek as proposed by armen.shimoon would work too in other cases when you are using stream immediately:
writer.Flush();
memoStream.Flush();
memoStream.Position = 0;
// do something with MemoryStream right here before either of `using`ends.

Related

System.IO.Compression.ZipArchive corrupt when downloading [duplicate]

I'm trying to create a zip stream on the fly with some byte array data and make it download via my MVC action.
But the downloaded file always gives the following corrupted error when opened in windows.
And this error when I try to xtract from 7z
But note that the files extracted from the 7z is not corrupted.
I'm using ZipArchive and the below is my code.
private byte[] GetZippedPods(IEnumerable<POD> pods, long consignmentID)
{
using (var zipStream = new MemoryStream())
{
//Create an archive and store the stream in memory.
using (var zipArchive = new ZipArchive(zipStream, ZipArchiveMode.Create, true))
{
int index = 1;
foreach (var pod in pods)
{
var zipEntry = zipArchive.CreateEntry($"POD{consignmentID}{index++}.png", CompressionLevel.NoCompression);
using (var originalFileStream = new MemoryStream(pod.ByteData))
{
using (var zipEntryStream = zipEntry.Open())
{
originalFileStream.CopyTo(zipEntryStream);
}
}
}
return zipStream.ToArray();
}
}
}
public ActionResult DownloadPOD(long consignmentID)
{
var pods = _consignmentService.GetPODs(consignmentID);
var fileBytes = GetZippedPods(pods, consignmentID);
return File(fileBytes, MediaTypeNames.Application.Octet, $"PODS{consignmentID}.zip");
}
What am I doing wrong here.
Any help would be highly appreciated as I'm struggling with this for a whole day.
Thanks in advance
Move zipStream.ToArray() outside of the zipArchive using.
The reason for your problem is that the stream is buffered. There's a few ways to deal wtih it:
You can set the stream's AutoFlush property to true.
You can manually call .Flush() on the stream.
Or, since it's MemoryStream and you're using .ToArray(), you can simply allow the stream to be Closed/Disposed first (which we've done by moving it outside the using).
I Dispose ZipArchive And error solved
public static byte[] GetZipFile(Dictionary<string, List<FileInformation>> allFileInformations)
{
MemoryStream compressedFileStream = new MemoryStream();
//Create an archive and store the stream in memory.
using (var zipArchive = new ZipArchive(compressedFileStream, ZipArchiveMode.Create, true))
{
foreach (var fInformation in allFileInformations)
{
var files = allFileInformations.Where(x => x.Key == fInformation.Key).SelectMany(x => x.Value).ToList();
for (var i = 0; i < files.Count; i++)
{
ZipArchiveEntry zipEntry = zipArchive.CreateEntry(fInformation.Key + "/" + files[i].FileName);
var caseAttachmentModel = Encoding.UTF8.GetBytes(files[i].Content);
//Get the stream of the attachment
using (var originalFileStream = new MemoryStream(caseAttachmentModel))
using (var zipEntryStream = zipEntry.Open())
{
//Copy the attachment stream to the zip entry stream
originalFileStream.CopyTo(zipEntryStream);
}
}
}
//i added this line
zipArchive.Dispose();
return compressedFileStream.ToArray();
}
}
public void SaveZipFile(){
var zipFileArray = Global.GetZipFile(allFileInformations);
var zipFile = new MemoryStream(zipFileArray);
FileStream fs = new FileStream(path + "\\111.zip",
FileMode.Create,FileAccess.Write);
zipFile.CopyTo(fs);
zipFile.Flush();
fs.Close();
zipFile.Close();
}
I was also having problems with this and I found my issue was not the generation of the archive itself but rather how I was handing my GET request in AngularJS.
This post helped me: how to download a zip file using angular
The key was adding responseType: 'arraybuffer' to my $http call.
factory.serverConfigExportZIP = function () {
return $http({
url: dataServiceBase + 'serverConfigExport',
method: "GET",
responseType: 'arraybuffer'
})
};
you can remove "using" and use Dispose and Close methods
it's work for me
...
zip.Dispose();
zipStream.Close();
return zipStream.ToArray();
I know this is a C# question but for managed C++, delete the ZipArchive^ after you're done with it to fix the error.
ZipArchive^ zar = ZipFile::Open(starget, ZipArchiveMode::Create);
ZipFileExtensions::CreateEntryFromFile(zar, sfile1, "file.txt");
ZipFileExtensions::CreateEntryFromFile(zar, sfile2, "file2.txt");
delete zar;
when i wanted to create zip file directly from MemoryStream which i used for ZipArchive i was getting error ( "unexpected end of data" or zero length file )
there are three points to get ride of this error
set the last parameter of ZipArchive constructor to true ( it leaves to leave stream open after ZipArchive disposed )
call dispose() on ZipArchive and dispose it manually.
create another MemoryStream based on which you set in ZipArchive constructor, by calling ToArray() method.
here is sample code :
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create,))
{
foreach (var s3Object in objectList.S3Objects)
{
var entry = archive.CreateEntry(s3Object.Key, CompressionLevel.NoCompression);
using (var entryStream = entry.Open())
{
var request = new GetObjectRequest { BucketName = command.BucketName, Key = s3Object.Key };
using (var getObjectResponse = await client.GetObjectAsync(request))
{
await getObjectResponse.ResponseStream.CopyToAsync(entryStream);
}
}
}
archive.Dispose();
using (var fileStream = new FileStream(outputFileName, FileMode.Create, FileAccess.Write))
{
var zipFileMemoryStream = new MemoryStream(memoryStream.ToArray());
zipFileMemoryStream.CopyTo(fileStream);
zipFileMemoryStream.Flush();
fileStream.Close();
zipFileMemoryStream.Close();
}
}
}
I had the same problem... In this case I just needed to move the ToArray() (byte[]) from MemoryStream outside the using (var zipArchive = new ZipArchive...
I think it is necessary for using related to ZipArchive to completely close and dispose of the file before converting it into a byte array

How to unzip a file in memory to an Azure CloudBlob [duplicate]

I'm probably doing something obviously stupid here. Please point it out!
I have some C# code that is pulling down a bunch of .gz files from SFTP (using the SSH.NET Nuget package - works great!). Each gz contains only a single .CSV file inside of them. I want to keep these files in memory without hitting disk (yes, I know, server memory management concerns exist - that's fine as these files are fairly small), decompress them in memory to extract the CSV file inside, and then return a collection of CSV files in a custom DTO (FtpFile).
My problem is that while my MemoryStream from the SFTP connection has data in it, either it doesn't ever seem to be populated in my GZipStream or the copy from the GZipStream to my output MemoryStream is failing. I have tried with the more traditional looping over Read with my own buffer but it had the same results as this code.
Aside from connection details (it connects successfully, so no worries there), here's all of my code:
Logic:
public static List<FtpFile> Foo()
{
var connectionInfo = new ConnectionInfo("example.com",
"username",
new PasswordAuthenticationMethod("username", "password"));
using (var client = new SftpClient(connectionInfo))
{
client.Connect();
var searchResults = client.ListDirectory("/testdir")
.Where(obj => obj.IsRegularFile
&& obj.Name.ToLowerInvariant().StartsWith("test_")
&& obj.Name.ToLowerInvariant().EndsWith(".gz"))
.Take(2)
.ToList();
var fileResults = new List<FtpFile>();
foreach (var file in searchResults)
{
var ftpFile = new FtpFile { FileName = file.Name, FileSize = file.Length };
using (var fileStream = new MemoryStream())
{
client.DownloadFile(file.FullName, fileStream); // Success! All is good here, so far. :)
using (var gzStream = new GZipStream(fileStream, CompressionMode.Decompress))
{
using (var outputStream = new MemoryStream())
{
gzStream.CopyTo(outputStream);
byte[] outputBytes = outputStream.ToArray(); // No data. Sad panda. :'(
ftpFile.FileContents = Encoding.ASCII.GetString(outputBytes);
fileResults.Add(ftpFile);
}
}
}
}
return fileResults;
}
}
FtpFile (just a simple DTO I'm populating):
public class FtpFile
{
public string FileName { get; set; }
public long FileSize { get; set; }
public string FileContents { get; set; }
}
PSA If anybody comes and copies this code, be aware that this is NOT good code in that you could have some serious memory management problems with this code! It's best practice to instead stream it to disk, which is not being done in this code! My needs are very specific in that I have to have these files simultaneously in memory for what I'm building with them.
If you are inserting data into the stream, make sure to seek back to its origin before un-gzipping it.
The following should fix your troubles:
using (var fileStream = new MemoryStream())
{
client.DownloadFile(file.FullName, fileStream); // Success! All is good here, so far. :)
fileStream.Seek(0, SeekOrigin.Begin);
using (var gzStream = new GZipStream(fileStream, CompressionMode.Decompress))
{
using (var outputStream = new MemoryStream())
{
gzStream.CopyTo(outputStream);
byte[] outputBytes = outputStream.ToArray(); // No data. Sad panda. :'(
ftpFile.FileContents = Encoding.ASCII.GetString(outputBytes);
fileResults.Add(ftpFile);
}
}
}

System.ObjectDisposedException: Cannot access a disposed object. Object name: 'Cannot access a closed file.'

I am working on web API core and returning IActionResult. One of my API throws error while returning FileResult.
I get the following error.
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'Cannot access a closed file.'.
My code is something like :
FileStream zipToOpen;
using (zipToOpen = new FileStream(Path.Combine(reportsPath, Guid.NewGuid().ToString()) + ".zip", FileMode.Create))
{
using (ZipArchive zipArchive = new ZipArchive(zipToOpen, ZipArchiveMode.Create, true))
{
foreach (var document in documents)
{
string fileName = string.Empty;
int index = document.Path.LastIndexOf("/");
if (index != -1)
fileName = document.Path.Substring(index + 1);
zipArchive.CreateEntryFromFile(document.Path, fileName);
}
}
//zipToOpen.Position = 0;
return File(zipToOpen, "application/zip", "MyDocuments.zip");
}
Can anyone please help me what's the issue.
As stated in another answer the file stream is being disposed of before the framework has had time to completed its functionality. That is because you are returning the stream in a using block which will dispose of the stream once the out of scope.
If there is no need for the archive to actually be saved/written to disk, consider building the archive in memory and return its stream.
//...
MemoryStream zipStream = new MemoryStream();
using (var zipArchive = new ZipArchive(zipStream, ZipArchiveMode.Create, leaveOpen: true)) {
foreach (var document in documents) {
string fileName = document.Path;
int index = fileName.LastIndexOf("/");
if (index != -1)
fileName = fileName.Substring(index + 1);
zipArchive.CreateEntryFromFile(document.Path, fileName);
}
} // disposal of archive will force data to be written to memory stream.
zipStream.Position = 0; //reset memory stream position.
return File(zipStream, "application/zip", "MyDocuments.zip");
Note the memory stream will be disposed by the FileResult once it is finished with it.
You're working with a stream, so until the stream is flushed or closed, you still need the component pieces like your ZipArchive. The problem is that you're returning the stream outside of the using statement where zipArchive sill exists. If you move your return inside that using block, you should be fine.

How to go from byte[], to MemoryStream, Unzip, then write to FileStream

I am unsure what I am doing wrong. The files that I create after grabbing a byte[] (which is emailAttachment.Body) and passing it to the method ExtractZipFile, converting it to MemoryStream and then unzipping it, returning it as a KeyValuePair and then Writing to a file using FileStream.
However when I go to open the new created files there is an error in opening them. They are not able to be opened.
The below are in the same class
using Ionic.Zip;
var extractedFiles = ExtractZipFile(emailAttachment.Body);
foreach (KeyValuePair<string, MemoryStream> extractedFile in extractedFiles)
{
string FileName = extractedFile.Key;
using (FileStream file = new FileStream(CurrentFileSystem +
FileName.FileFullPath(),FileMode.Create, System.IO.FileAccess.Write))
{
byte[] bytes = new byte[extractedFile.Value.Length];
extractedFile.Value.Read(bytes, 0, (int) xtractedFile.Value.Length);
file.Write(bytes,0,bytes.Length);
extractedFile.Value.Close();
}
}
private Dictionary<string, MemoryStream> ExtractZipFile(byte[] messagePart)
{
Dictionary<string, MemoryStream> result = new Dictionary<string,MemoryStream>();
MemoryStream data = new MemoryStream(messagePart);
using (ZipFile zip = ZipFile.Read(data))
{
foreach (ZipEntry ent in zip)
{
MemoryStream memoryStream = new MemoryStream();
ent.Extract(memoryStream);
result.Add(ent.FileName,memoryStream);
}
}
return result;
}
Is there something I am missing? I do not want to save the original zip file just the extracted Files from MemoryStream.
What am I doing wrong?
After writing to your MemoryStream, you're not setting the position back to 0:
MemoryStream memoryStream = new MemoryStream();
ent.Extract(memoryStream);
result.Add(ent.FileName,memoryStream);
Because of this, the stream position will be at the end when you try to read from it, and you'll read nothing. Make sure to rewind it:
memoryStream.Position = 0;
Also, you don't have to handle the copy manually. Just let the CopyTo method take care of it:
extractedFile.Value.CopyTo(file);
I'd suggest that you clean up your use of MemoryStream in your code.
I agree that calling memoryStream.Position = 0; will allow this code to work correctly, but it's an easy thing to miss when reading and writing memory streams.
It's better to write code that avoids the bug.
Try this:
private IEnumerable<(string Path, byte[] Content)> ExtractZipFile(byte[] messagePart)
{
using (var data = new MemoryStream(messagePart))
{
using (var zipFile = ZipFile.Read(data))
{
foreach (var zipEntry in zipFile)
{
using (var memoryStream = new MemoryStream())
{
zipEntry.Extract(memoryStream);
yield return (Path: zipEntry.FileName, Content: memoryStream.ToArray());
}
}
}
}
}
Then your calling code would look something like this:
foreach (var extractedFile in ExtractZipFile(emailAttachment.Body))
{
File.WriteAllBytes(Path.Combine(CurrentFileSystem, extractedFile.Path.FileFullPath()), extractedFile.Content);
}
It's just a lot less code and a much better chance of avoiding bugs. The number one predictor of bugs in code is the number of lines of code you write.
Since I find it all a lot of code for a simple operation, here's my two cents.
using Ionic.Zip;
using (var s = new MemoryStream(emailAttachment.Body))
using (ZipFile zip = ZipFile.Read(s))
{
foreach (ZipEntry ent in zip)
{
string path = Path.Combine(CurrentFileSystem, ent.FileName.FileFullPath())
using (FileStream file = new FileStream(path, FileAccess.Write))
{
ent.Extract(file);
}
}
}

ZipArchive Created with System.IO.Compression is Damaged

I am having a hard time creating a ZipArchive successfully on Asp.net core MVC. I have an excel file generated with data that works and I need to put in an archive. This is what I've done so far
public FileResult ExportGoodsReceiptData()
{
var records = _salesService.GetAllReceipts();
var lineRecords = _salesService.GetAllReceiptLines();
var result = _salesService.ExportGoodsReceiptData(records);
var lineResult = _salesService.ExportGoodsReceiptLineData(lineRecords);
byte[] resultArr = StreamToByteArray(result);
byte[] lineResultArr = StreamToByteArray(lineResult);
using(MemoryStream stream = new MemoryStream())
{
using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, true))
{
var zipArchiveEntry = archive.CreateEntry("GoodsReceipts.csv", CompressionLevel.Fastest);
using (var zipStream = zipArchiveEntry.Open())
using (var resultCom = new MemoryStream(resultArr))
{
resultCom.CopyTo(zipStream);
}
}
return new FileStreamResult(stream, "application/zip") { FileDownloadName = "GoodsReceiptsArchive.zip" };
}
}
When I run it, I get the zipfile, but can't open it. It throws error stating that it may have been damaged. I debugged the code to notice that one of the properties (length property) throws an invalidOperation exception. My approach looks identical to most samples I found online. Don't know how else to solve this. Please help.
Your problem is that you're disposing of your memory stream before you return it. Remove this using:
using(MemoryStream stream = new MemoryStream())
Replace it with:
var stream = new MemoryStream();
Asp.Net MVC will automatically dispose of the stream for you.

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