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How to check folder is present in Azure blob container

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Posted on by CU21091228-0

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Hi Team,

Inside the azure blob container name i am having multiple folders, like below.

ContinerName/Folder1/Folder2

In case of any folder is missing i would like to show some error message.

In above if Folder2 is missing show error like folder is not present.

Below is the code which i am using.

using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Auth;
using Microsoft.WindowsAzure.Storage.Blob;
using Microsoft.WindowsAzure.Storage.File;


 public void checkFolderName(str _filePath)
 {
     CloudBlobContainer blobcontainer;
     CloudBlobClient    blobClient;
      
     
     var credential     = new StorageCredentials("StorageAccountName", "StorageAccessKey");
     var storageAccount = new CloudStorageAccount(credential, true);
     blobClient         = storageAccount.CreateCloudBlobClient();
     blobcontainer      = blobClient.GetContainerReference(_filePath);
  }

Please let me know how to achieve this.

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Jonas "Jones" Melgaard 4,930 Most Valuable Professional on at

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Folders in containers are not how you normally think of folders (I.e. they do not exist if there is no blobs in them).

But if you want to check, you can use the method 'blobContainer.GetBlobDirectoryReference('path')' and check if any blobs are returned.

There are examples on StackOverflow if you need it.

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Martin Dráb 237,807 Most Valuable Professional on at

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There aren't actually folders in blob containers. For example, Folder1/file.txt is simply a blob named Folder1/file.txt, not file.txt blob in a folder.

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CU21091228-0 230 on at

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Below code i am using.

CloudBlobDirectory cloudBlobDirectory = blobContainer.GetBlobDirectoryReference('Folder1/Folder2'); if (!cloudBlobDirectory) { throw error ("Folder name not found"); }

In case folder path is not present i am not getting any error, please let me know where i am wrong.

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Martin Dráb 237,807 Most Valuable Professional on at

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Let me quote an answer from StackOverflow:

In blob storage, directories don't exist as an item by themselves. What you can have is a blob that has a name that can be interpreted as being in a directory. If you look at the underlying REST API you'll see that that there's nothing in there about directories. What the storage client library is doing for you is searching for blobs that start with the directory name then the delimiter e.g. "DirectoryA/DirectoryB/FileName.txt". What this means is that for a directory to exist it must contain a blob. To check if the directory exists you can try either:

var blobDirectory = client.GetBlobDirectoryReference("Path_to_dir");
bool directoryExists = blobDirectory.ListBlobs().Count() > 0

or

bool directoryExists = client.ListBlobsWithPrefix("DirectoryA/DirectoryB/").Count();

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CU21091228-0 230 on at

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I try like below.

boolean directoryExists = CloudBlobDirectory.ListBlobs().Count() > 0

But Ax is not support .Count() after ListBlobs().

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Martin Dráb 237,807 Most Valuable Professional on at

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Split it to two calls. For example:
var blobs = CloudBlobDirectory.ListBlobs(); boolean directoryExists = blobs.Count() > 0;

It'll likely fix your problem. If not, please describe the problem to us.

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CU21091228-0 230 on at

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In Azure blob container having multiple folders, i would like to check those folder is present or not, if not present throw a error.

Below us my AX code.

using Microsoft.WindowsAzure.Storage; using Microsoft.WindowsAzure.Storage.Auth; using Microsoft.WindowsAzure.Storage.Blob; using Microsoft.WindowsAzure.Storage.File; public void checkFolderName(str _filePath, str _containerName) { CloudBlobContainer blobcontainer; CloudBlobClient blobClient; var credential = new StorageCredentials("StorageAccountName", "StorageAccessKey"); var storageAccount = new CloudStorageAccount(credential, true); blobClient = storageAccount.CreateCloudBlobClient(); blobcontainer = blobClient.GetContainerReference(_containerName); CloudBlobDirectory cloudBlobDirectory = blobContainer.GetBlobDirectoryReference(_filePath); }

I try below code, Ax is not supporting blobs.count()

var blobs = CloudBlobDirectory.ListBlobs(false, 0, null, null); boolean directoryExists = blobs.Count() > 0;

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Martin Dráb 237,807 Most Valuable Professional on at

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I'm sorry, but "Ax is not supporting blobs.count()" is not a good description of a problem. Please tell us what happened. For example, did you get a compilation error a runtime exception? What did the error message said?

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Martin Dráb 237,807 Most Valuable Professional on at

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I think I see your problem. Your code (the call of ListBlobs()) assumes that you're using Microsoft.Azure.Storage.Blob.CloudBlobDirectory, but you aren't. You're using CloudBlobDirectory from Microsoft.WindowsAzure.Storage.Blob namespace.

Note that the latest library for this purpose is Azure.Storage.Blobs. I think that the solution there is using BlobContainerClient.GetBlobs() with the folder path in the prefix parameter.

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CU21091228-0 230 on at

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I have added below code.

Using Azure.Storage.Blobs; public void checkFolderName(str _filePath, str _containerName) { BlobContainerClient blobContainerClient; // blobContainerClient.GetBlobs(_filePath); }

Below error i am getting.

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