Question

我想检查Azure Blob存储中是否存在特定文件。是否可以通过指定文件名进行检查？每次我都找不到文件错误。

Answer 1

var blob = client.GetContainerReference(containerName).GetBlockBlobReference(blobFileName);

if (blob.Exists())
 //do your stuff

Answer 2

此扩展方法可以帮助您：

public static class BlobExtensions
{
    public static bool Exists(this CloudBlob blob)
    {
        try
        {
            blob.FetchAttributes();
            return true;
        }
        catch (StorageClientException e)
        {
            if (e.ErrorCode == StorageErrorCode.ResourceNotFound)
            {
                return false;
            }
            else
            {
                throw;
            }
        }
    }
}

用法：

static void Main(string[] args)
{
    var blob = CloudStorageAccount.DevelopmentStorageAccount
        .CreateCloudBlobClient().GetBlobReference(args[0]);
    // or CloudStorageAccount.Parse("<your connection string>")

    if (blob.Exists())
    {
        Console.WriteLine("The blob exists!");
    }
    else
    {
        Console.WriteLine("The blob doesn't exist.");
    }
}

http://blog.smarx.com/posts/testing-existence-of-a-windows-azure-blob

Answer 3

使用更新的SDK，一旦您拥有CloudBlobReference，您就可以在引用上调用Exists（）。

<强>更新

相关文档已移至https://docs.microsoft.com/en-us/dotnet/api/microsoft.windowsazure.storage.blob.cloudblob.exists?view=azurestorage-8.1.3#Microsoft_WindowsAzure_Storage_Blob_CloudBlob_Exists_Microsoft_WindowsAzure_Storage_Blob_BlobRequestOptions_Microsoft_WindowsAzure_Storage_OperationContext_

我使用WindowsAzure.Storage v2.0.6.1实现

    private CloudBlockBlob GetBlobReference(string filePath, bool createContainerIfMissing = true)
    {
        CloudBlobClient client = _account.CreateCloudBlobClient();
        CloudBlobContainer container = client.GetContainerReference("my-container");

        if ( createContainerIfMissing && container.CreateIfNotExists())
        {
            //Public blobs allow for public access to the image via the URI
            //But first, make sure the blob exists
            container.SetPermissions(new BlobContainerPermissions { PublicAccess = BlobContainerPublicAccessType.Blob });
        }

        CloudBlockBlob blob = container.GetBlockBlobReference(filePath);

        return blob;
    }

    public bool Exists(String filepath)
    {
        var blob = GetBlobReference(filepath, false);
        return blob.Exists();
    }

Answer 4

使用CloudBlockBlob的➜ bitmagic git:(master) ✗ time ./next-1 ./next-1 4.27s user 0.01s system 99% cpu 4.313 total ➜ bitmagic git:(master) ✗ time ./next-2 ./next-2 12.42s user 0.00s system 99% cpu 12.436 total方法。

ExistsAsync

Answer 5

使用 Microsoft.WindowsAzure.Storage.Blob版本4.3.0.0 ，以下代码应该可以使用（对于此程序集的旧版本，有很多重大更改）：

使用容器/ blob名称和给定的API（现在看来微软已经实现了这个）：

return _blobClient.GetContainerReference(containerName).GetBlockBlobReference(blobName).Exists();

使用blob URI（解决方法）：

  try 
  {
      CloudBlockBlob cb = (CloudBlockBlob) _blobClient.GetBlobReferenceFromServer(new Uri(url));
      cb.FetchAttributes();
  }
  catch (StorageException se)
  {
      if (se.Message.Contains("404") || se.Message.Contains("Not Found"))
      {
          return false;
      }
   }
   return true;

（如果blob不存在，则获取属性将失败。很脏，我知道:)。

Answer 6

使用新软件包Azure.Storage.Blobs

BlobServiceClient blobServiceClient = new BlobServiceClient("YourStorageConnectionString");
BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient("YourContainerName");
BlobClient blobClient = containerClient.GetBlobClient("YourFileName");

然后检查是否存在

if (blobClient.Exists()){
 //your code
}

Answer 7

对于最新版本的SDK，您需要使用ExistsAsync方法，

public async Task<bool> FileExists(string fileName)
{
    return  await directory.GetBlockBlobReference(fileName).ExistsAsync();
}

这里是code sample。

Answer 8

## dbutils.widgets.get to call the key-value from data bricks job

storage_account_name= dbutils.widgets.get("storage_account_name")
container_name= dbutils.widgets.get("container_name")
transcripts_path_intent= dbutils.widgets.get("transcripts_path_intent")
# Read azure blob access key from dbutils 
storage_account_access_key = dbutils.secrets.get(scope = "inteliserve-blob-storage-secret-scope", key = "storage-account-key")

from azure.storage.blob import BlockBlobService
block_blob_service = BlockBlobService(account_name=storage_account_name, account_key=storage_account_access_key)

def blob_exists():
        container_name2 = container_name
        blob_name = transcripts_path_intent
        exists=(block_blob_service.exists(container_name2, blob_name))
        return exists
blobstat = blob_exists()
print(blobstat)

如何检查Azure Blob文件是否存在

8 个答案: