如何将对象传输到 Azure Blob 存储而不将文件保存在本地存储上? [英] How to transfer objects to Azure Blob Storage without saving file on local storage?

问题描述

我一直在关注这个来自GitHub的示例来传输文件到 Azure Blob 存储.该程序在本地 MyDocuments 文件夹中创建一个文件以上传到 Blob 容器.创建文件后，它会将其上传到容器.是否可以在内存中创建 JSON 对象并将它们发送到 Azure Blob 存储，而无需先将该文件写入硬盘?

I have been following this example from GitHub to transfer files to Azure Blob Storage. The program creates a file in the local MyDocuments folder to upload to a blob container. After the file is created it uploads it to the container. Is it possible to create JSON objects in memory and send them to Azure Blob Storage without writing that file to the hard drive first?

namespace storage_blobs_dotnet_quickstart
{
    using Microsoft.Azure.Storage;
    using Microsoft.Azure.Storage.Blob;
    using System;
    using System.IO;
    using System.Threading.Tasks;

    public static class Program
    {
        public static void Main()
        {
            Console.WriteLine("Azure Blob Storage - .NET quickstart sample");
            Console.WriteLine();
            ProcessAsync().GetAwaiter().GetResult();

            Console.WriteLine("Press any key to exit the sample application.");
            Console.ReadLine();
        }

        private static async Task ProcessAsync()
        {
            CloudStorageAccount storageAccount = null;
            CloudBlobContainer cloudBlobContainer = null;
            string sourceFile = null;
            string destinationFile = null;

            // Retrieve the connection string for use with the application. The storage connection string is stored
            // in an environment variable on the machine running the application called storageconnectionstring.
            // If the environment variable is created after the application is launched in a console or with Visual
            // Studio, the shell needs to be closed and reloaded to take the environment variable into account.
            string storageConnectionString = Environment.GetEnvironmentVariable("storageconnectionstring");

            // Check whether the connection string can be parsed.
            if (CloudStorageAccount.TryParse(storageConnectionString, out storageAccount))
            {
                try
                {
                    // Create the CloudBlobClient that represents the Blob storage endpoint for the storage account.
                    CloudBlobClient cloudBlobClient = storageAccount.CreateCloudBlobClient();

                    // Create a container called 'quickstartblobs' and append a GUID value to it to make the name unique. 
                    cloudBlobContainer = cloudBlobClient.GetContainerReference("quickstartblobs" + Guid.NewGuid().ToString());
                    await cloudBlobContainer.CreateAsync();
                    Console.WriteLine("Created container '{0}'", cloudBlobContainer.Name);
                    Console.WriteLine();

                    // Set the permissions so the blobs are public. 
                    BlobContainerPermissions permissions = new BlobContainerPermissions
                    {
                        PublicAccess = BlobContainerPublicAccessType.Blob
                    };
                    await cloudBlobContainer.SetPermissionsAsync(permissions);

                    // Create a file in your local MyDocuments folder to upload to a blob.
                    string localPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
                    string localFileName = "QuickStart_" + Guid.NewGuid().ToString() + ".txt";
                    sourceFile = Path.Combine(localPath, localFileName);
                    // Write text to the file.
                    File.WriteAllText(sourceFile, "Hello, World!");

                    Console.WriteLine("Temp file = {0}", sourceFile);
                    Console.WriteLine("Uploading to Blob storage as blob '{0}'", localFileName);
                    Console.WriteLine();

                    // Get a reference to the blob address, then upload the file to the blob.
                    // Use the value of localFileName for the blob name.
                    CloudBlockBlob cloudBlockBlob = cloudBlobContainer.GetBlockBlobReference(localFileName);
                    await cloudBlockBlob.UploadFromFileAsync(sourceFile);

                    // List the blobs in the container.
                    Console.WriteLine("Listing blobs in container.");
                    BlobContinuationToken blobContinuationToken = null;
                    do
                    {
                        var resultSegment = await cloudBlobContainer.ListBlobsSegmentedAsync(null, blobContinuationToken);
                        // Get the value of the continuation token returned by the listing call.
                        blobContinuationToken = resultSegment.ContinuationToken;
                        foreach (IListBlobItem item in resultSegment.Results)
                        {
                            Console.WriteLine(item.Uri);
                        }
                    } while (blobContinuationToken != null); // Loop while the continuation token is not null.
                    Console.WriteLine();

                    // Download the blob to a local file, using the reference created earlier. 
                    // Append the string "_DOWNLOADED" before the .txt extension so that you can see both files in MyDocuments.
                    destinationFile = sourceFile.Replace(".txt", "_DOWNLOADED.txt");
                    Console.WriteLine("Downloading blob to {0}", destinationFile);
                    Console.WriteLine();
                    await cloudBlockBlob.DownloadToFileAsync(destinationFile, FileMode.Create);
                }
                catch (StorageException ex)
                {
                    Console.WriteLine("Error returned from the service: {0}", ex.Message);
                }
                finally
                {
                    Console.WriteLine("Press any key to delete the sample files and example container.");
                    Console.ReadLine();
                    // Clean up resources. This includes the container and the two temp files.
                    Console.WriteLine("Deleting the container and any blobs it contains");
                    if (cloudBlobContainer != null)
                    {
                        await cloudBlobContainer.DeleteIfExistsAsync();
                    }
                    Console.WriteLine("Deleting the local source file and local downloaded files");
                    Console.WriteLine();
                    File.Delete(sourceFile);
                    File.Delete(destinationFile);
                }
            }
            else
            {
                Console.WriteLine(
                    "A connection string has not been defined in the system environment variables. " +
                    "Add a environment variable named 'storageconnectionstring' with your storage " +
                    "connection string as a value.");
            }
        }
    }
}

推荐答案

还有一些其他内置方法可以上传到 blob 存储，而无需先存储在本地驱动器中.

There are some other built-in methods for uploading to blob storage without storing in local drive first.

对于您的情况，您可以考虑以下内置方法:

For your case, you can consider the following built-in methods:

1.上传流(示例见此处):

1.For uploading stream(for samples, see here):

UploadFromStream / UploadFromStreamAsync

2.上传字符串/文本(示例见此处):

2.For uploading string / text(for samples, see here):

UploadText / UploadTextAsync

这篇关于如何将对象传输到 Azure Blob 存储而不将文件保存在本地存储上?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！