Saving File Using Bucket, i am able to save file and content type to database, But Not Able to download file with their extension(content)

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Oct 27, 2017, 2:32:10 AM10/27/17

to mongodb-user

Help me how to get content type column value at download time ?

public void DownloadFileFromMongoDb(string DatabaseName, string Coll_or_ChunkNam, ObjectId FileID)

{

IMongoDatabase database = ConnectMongoDatabase(DatabaseName);

var BUcket_Option = new GridFSBucketOptions

{

BucketName = Coll_or_ChunkNam,

WriteConcern = WriteConcern.WMajority,

ReadPreference = ReadPreference.Secondary

// ChunkSizeBytes = 1048576, // 1MB

};

IGridFSBucket bucket = new GridFSBucket(database, BUcket_Option);

if (FileID != null)

{

byte[] buffer = ReadFully(bucket.OpenDownloadStream(FileID));

string mimeType = string.Empty;

System.Web.HttpContext.Current.Response.Buffer = true;

System.Web.HttpContext.Current.Response.Clear();

System.Web.HttpContext.Current.Response.ContentType = mimeType;

System.Web.HttpContext.Current.Response.AddHeader("content-disposition", "attachment; filename=" + FileID + ".pdf");

System.Web.HttpContext.Current.Response.BinaryWrite(buffer); // create the file

System.Web.HttpContext.Current.Response.Flush();

}

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Nov 2, 2017, 9:00:45 PM11/2/17

to mongodb-user

System.Web.HttpContext.Current.Response.ContentType = mimeType;

If I understand correctly, you need to set the mimeType variable to the proper content type. However the contentType field in the database is not a proper MIME type. See https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types for a description of valid MIME types.

You didn’t specify how you query the relevant file, but in the mongo shell the code should look similar to:

var file = db.Txt.files.findOne({_id: <the file _id>})
var contentType = file.contentType

If executed in the mongo shell, the contentType variable should contain e.g. .txt as stored in the database.

System.Web.HttpContext.Current.Response.AddHeader(“content-disposition”, “attachment; filename=” + FileID + “.pdf”);

Having said that, I’m not sure I understand why the pdf extension is hardcoded in the next line. Is this intentional?

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