I am trying to download .eml files (message.mimecontent) from an Exchange Server and upload it to a SharePoint document library. One option is saving the file to local drive and then uploading it from a filestream.
Is there a way that I can convert mimecontent to a filestream without saving it as a file first ? This would make the code much nicer avoiding all intricacies of file operations, file name management etc.
Assuming you are using EWS, the mime content is actually a byte[]. See the Content property.
Without saving this byte[] to the file system, keep it in memory, and use this SPFileCollection.Add method overload to upload a file to the SharePoint site by providing the byte[] as input.
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I want to download a single file in a remote Zip file that is in the cloud. The zip file is too large for me to download as a whole therefore I have decided to look for a way to download only a single file(XML) that I need within the archive. I have tried and Tested a webclient and web request but it downloads the whole zip file(also too large file for these technuques usually fails). I'm eyeing the SharpZipLib but I dont know how to use it. Is it the right library I should use or there are other available ones I can get and test. Thank you so much.
Here is my case:
I'm using ABCPDF to generate a HTML document from a .DOCX file that I need to show on the web.
When you export to HTML from ABCPDF you generate a HTML and a folder with support files (.css, .js, .png)
Now these HTML files may contain quite sensitive data so I immediately after generating the files, I move them to a password-protected .zip file (from which I fetch them later)
The problem is, that this leaves the files unencrypted on the HDD for a few seconds and even longer if I'm (for some reason) unable to delete them at once.
I'd like suggestions for another way of doing this. I've looked in to a ram drive, but I'm not happy with installing such drivers on my servers. (AND the RAM drive would still be accessible from the OS)
The cause of the problem here might be that ABCPDF can only export HTML as files (since its multiple files) and not as a stream.
Any ideas?
I'm using .NET 4.6.x and c#
Since all your files except the .HTML are anonymous, you can use the suggested way of writing the HTML to a stream. Only all other files will be stored to the file system.
http://www.websupergoo.com/helppdfnet/source/5-abcpdf/doc/1-methods/save.htm
When saving to a Stream the format can be indicated using a Doc.SaveOptions.FileExtension property such as ".htm" or ".xps". For HTML you must provide a sensible value for the Doc.SaveOptions.Folder property.
http://www.websupergoo.com/helppdfnet/source/5-abcpdf/xsaveoptions/2-properties/folder.htm
This property specifies the folder where to store additional data such as images and fonts. it is only used when exporting documents to HTML. It is ignored otherwise.
For a start, try using a simple MemoryStream to hold the sensitive data. If you get large files or high traffic, open an encrypted stream to a file on your system.
Assuming I'm just saving files to a web server.
What is the difference of saving an uploaded file using the SaveAs method versus processing the file via InputStream?
Is there a performance difference?
Can both accomplish large file size uploading?
What is the difference of saving an uploaded file using the SaveAs method versus processing the file via InputStream?
Using SaveAs will just push the file to the file system. Processing using the input stream will allow you to perform any number of tasks - save to the file system, write to another stream, etc.
Is there a performance difference?
Depends on what you do. If you're comparing SaveAs to manually saving the file using the stream, then the difference is negligible.
Can both accomplish large file size uploading?
Yes.
Suppose, I have a list of MP3 files on my server. And I want a user to download multiple files (which he wants through any means). For, this what i want is to create the zip file dynamically and while saving it into the Output Stream using the dotnetzip or ioniczip libraries.
Well, that's not the perfect solution if the zip file got heavy in size. As, in that scenario the server doesn't support resumable downloads. So, to overcome this approach, I need to handle the zip file structure internally and provide the resume support.
So, is there any library (open source) which i can use to provide resumable dyanamic zip files stream directly to the Output Stream. Or, if possible I will be happy if someone let me know the structure of zip file specially the header content + data content.
Once a download has started, you should not alter the ZIP file anymore. Because then a resume will just result in a broken ZIP file. So make sure your dynamically created ZIP file stays available!
The issue of providing resume-functionality was solved in this article for .NET 1.1, and it is still valid and functional.
I have got stuck in a problem while downloading documents from database.
Currently I'm working in ASP.net project and this is my first career project.
We have some documents which we store in database. The documents(.pdf,.doc,.png,.docx,xls,xlsx) are stored in binary format with their type specified.
I can download one document using Response.write. But now i have to concatenate some documents and then allow user to download on button click.
I have googled a lot. Developers have said that this is impossible. But still i feel that this can be done.
However if this is impossible i thought that i will save these individual documents first at some server location and then zip them and then allow user to download. But how would i be able to save the individual document in their original format at server location.
Please help me out. I'm in big problem.
It is not impossible to read more than one document from a database and zip them up before presenting the zip file to the response stream. You can do this all in process, there is no need to save the documents to the server.
This code uses Ionic.Zip to zip up several files and write them to a MemoryStream:
foreach (var file in files)
{
zipFile.AddEntry(file.FileName, file.ContentBytes); // these are the file bytes
}
var zipMs = new MemoryStream();
zipFile.Save(zipMs);
zipMs.Seek(0, SeekOrigin.Begin);
zipMs.Flush();
The file.FileName includes the extensions (.docx) of the documents and when downloading through the browser, everything is displayed and saved correctly.