Azure Storage Blobs: Sample Code

This page provides sample code snippets to demonstrate common operations with Azure Blob Storage. Choose your preferred language to see the relevant examples.

C# Samples

1. Install the SDK

You'll need the Azure.Storage.Blobs NuGet package. Install it using the .NET CLI:

dotnet add package Azure.Storage.Blobs

2. Connect to your Blob Storage Account

Use your connection string to create a BlobServiceClient.

using Azure.Storage.Blobs;

// Replace with your actual connection string
string connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);

3. Upload a Blob

Create a container (if it doesn't exist) and upload a file.

using Azure.Storage.Blobs;
using System.IO;

// Get a client for a specific container
string containerName = "mycontainer";
BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
await containerClient.CreateIfNotExistsAsync();

// Get a client for a specific blob
string blobName = "my-blob.txt";
BlobClient blobClient = containerClient.GetBlobClient(blobName);

// Create a local file to upload
string localFilePath = "path/to/local/file.txt";
using (FileStream uploadFileStream = File.OpenRead(localFilePath))
{
    await blobClient.UploadAsync(uploadFileStream, true);
}

Console.WriteLine($"Uploaded blob '{blobName}' to container '{containerName}'.");

4. Download a Blob

Download the content of a blob to a local file.

using Azure.Storage.Blobs;
using System.IO;

string containerName = "mycontainer";
string blobName = "my-blob.txt";
string downloadFilePath = "path/to/downloaded/file.txt";

BlobClient blobClient = blobServiceClient.GetBlobContainerClient(containerName).GetBlobClient(blobName);

using (var downloadFileStream = File.OpenWrite(downloadFilePath))
{
    Response download = await blobClient.DownloadAsync();
    await download.Value.Content.CopyToAsync(downloadFileStream);
}

Console.WriteLine($"Downloaded blob '{blobName}' to '{downloadFilePath}'.");

5. List Blobs in a Container

Iterate through all blobs in a specified container.

using Azure.Storage.Blobs;

string containerName = "mycontainer";
BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);

Console.WriteLine("Blobs in container:");
await foreach (BlobItem blobItem in containerClient.GetBlobsAsync())
{
    Console.WriteLine($" - {blobItem.Name}");
}

Python Samples

1. Install the SDK

Use pip to install the Azure Blob Storage client library.

pip install azure-storage-blob

2. Connect to your Blob Storage Account

Use your connection string to create a BlobServiceClient.

from azure.storage.blob import BlobServiceClient

# Replace with your actual connection string
connect_str = "YOUR_AZURE_STORAGE_CONNECTION_STRING"
blob_service_client = BlobServiceClient.from_connection_string(connect_str)

3. Upload a Blob

Create a container (if it doesn't exist) and upload a file.

from azure.storage.blob import BlobServiceClient

container_name = "mycontainer"
blob_name = "my-blob.txt"
local_file_name = "path/to/local/file.txt"

# Get a client for a specific container
container_client = blob_service_client.get_container_client(container_name)
container_client.create_container(public_access="Container") # Create if it doesn't exist

# Upload the blob
with open(local_file_name, "rb") as data:
    blob_client = container_client.upload_blob(name=blob_name, data=data)

print(f"Uploaded blob '{blob_name}' to container '{container_name}'.")

4. Download a Blob

Download the content of a blob to a local file.

from azure.storage.blob import BlobServiceClient

container_name = "mycontainer"
blob_name = "my-blob.txt"
download_file_path = "path/to/downloaded/file.txt"

blob_client = blob_service_client.get_container_client(container_name).get_blob_client(blob_name)

with open(download_file_path, "wb") as download_file:
    download_stream = blob_client.download_blob()
    download_file.write(download_stream.readall())

print(f"Downloaded blob '{blob_name}' to '{download_file_path}'.")

5. List Blobs in a Container

Iterate through all blobs in a specified container.

from azure.storage.blob import BlobServiceClient

container_name = "mycontainer"
container_client = blob_service_client.get_container_client(container_name)

print("Blobs in container:")
blob_list = container_client.list_blobs()
for blob in blob_list:
    print(f" - {blob.name}")

JavaScript Samples

1. Install the SDK

Use npm or yarn to install the Azure Blob Storage client library.

npm install @azure/storage-blob

2. Connect to your Blob Storage Account

Use your connection string to create a BlobServiceClient.

import { BlobServiceClient } from "@azure/storage-blob";

// Replace with your actual connection string
const connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
const blobServiceClient = BlobServiceClient.fromConnectionString(connectionString);

3. Upload a Blob

Create a container (if it doesn't exist) and upload a file.

import { BlobServiceClient } from "@azure/storage-blob";
import { fileURLToPath } from 'url';
import { dirname } from 'path';
import * as fs from 'fs';

const connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
const blobServiceClient = BlobServiceClient.fromConnectionString(connectionString);

const containerName = "mycontainer";
const blobName = "my-blob.txt";
const localFilePath = "path/to/local/file.txt";

async function uploadBlob() {
    const containerClient = blobServiceClient.getContainerClient(containerName);
    await containerClient.createIfNotExists();

    const blobClient = containerClient.getBlobClient(blobName);
    const fileContent = fs.readFileSync(localFilePath);

    await blobClient.upload(fileContent, fileContent.length);
    console.log(`Uploaded blob '${blobName}' to container '${containerName}'.`);
}

uploadBlob().catch(console.error);

4. Download a Blob

Download the content of a blob to a local file.

import { BlobServiceClient } from "@azure/storage-blob";
import * as fs from 'fs';

const connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
const blobServiceClient = BlobServiceClient.fromConnectionString(connectionString);

const containerName = "mycontainer";
const blobName = "my-blob.txt";
const downloadFilePath = "path/to/downloaded/file.txt";

async function downloadBlob() {
    const blobClient = blobServiceClient.getContainerClient(containerName).getBlobClient(blobName);
    const downloadResponse = await blobClient.download();
    const downloadedContent = await downloadResponse.blobBody;
    const buffer = await downloadedContent.arrayBuffer();

    fs.writeFileSync(downloadFilePath, Buffer.from(buffer));
    console.log(`Downloaded blob '${blobName}' to '${downloadFilePath}'.`);
}

downloadBlob().catch(console.error);

5. List Blobs in a Container

Iterate through all blobs in a specified container.

import { BlobServiceClient } from "@azure/storage-blob";

const connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
const blobServiceClient = BlobServiceClient.fromConnectionString(connectionString);

const containerName = "mycontainer";

async function listBlobs() {
    const containerClient = blobServiceClient.getContainerClient(containerName);
    console.log("Blobs in container:");
    for await (const blobItem of containerClient.listBlobs()) {
        console.log(` - ${blobItem.name}`);
    }
}

listBlobs().catch(console.error);

Java Samples

1. Add Dependencies

Add the Azure Blob Storage dependency to your pom.xml file.

<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-storage-blob</artifactId>
    <version>12.27.0</version><!-- Use the latest version -->
</dependency>

2. Connect to your Blob Storage Account

Use your connection string to create a BlobServiceClient.

import com.azure.storage.blob.BlobServiceClient;
import com.azure.storage.blob.BlobServiceClientBuilder;

// Replace with your actual connection string
String connectionString = "YOUR_AZURE_STORAGE_CONNECTION_STRING";
BlobServiceClient blobServiceClient = new BlobServiceClientBuilder()
    .connectionString(connectionString)
    .buildClient();

3. Upload a Blob

Create a container (if it doesn't exist) and upload a file.

import com.azure.storage.blob.BlobClient;
import com.azure.storage.blob.BlobContainerClient;
import com.azure.storage.blob.BlobServiceClient;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

String containerName = "mycontainer";
String blobName = "my-blob.txt";
String localFilePath = "path/to/local/file.txt";

// Get a client for a specific container
BlobContainerClient containerClient = blobServiceClient.getBlobContainerClient(containerName);
containerClient.createIfNotExists();

// Get a client for a specific blob
BlobClient blobClient = containerClient.getBlobClient(blobName);

try {
    File file = new File(localFilePath);
    FileInputStream fileInputStream = new FileInputStream(file);
    blobClient.upload(fileInputStream, file.length());
    System.out.println("Uploaded blob '" + blobName + "' to container '" + containerName + "'.");
} catch (FileNotFoundException e) {
    e.printStackTrace();
}

4. Download a Blob

Download the content of a blob to a local file.

import com.azure.storage.blob.BlobClient;
import com.azure.storage.blob.BlobContainerClient;
import com.azure.storage.blob.BlobServiceClient;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

String containerName = "mycontainer";
String blobName = "my-blob.txt";
String downloadFilePath = "path/to/downloaded/file.txt";

BlobClient blobClient = blobServiceClient.getBlobContainerClient(containerName).getBlobClient(blobName);
File downloadFile = new File(downloadFilePath);

try (FileOutputStream fos = new FileOutputStream(downloadFile)) {
    blobClient.downloadStream(fos);
    System.out.println("Downloaded blob '" + blobName + "' to '" + downloadFilePath + "'.");
} catch (IOException e) {
    e.printStackTrace();
}

5. List Blobs in a Container

Iterate through all blobs in a specified container.

import com.azure.storage.blob.BlobClient;
import com.azure.storage.blob.BlobContainerClient;
import com.azure.storage.blob.BlobServiceClient;
import com.azure.storage.blob.models.BlobItem;

String containerName = "mycontainer";
BlobContainerClient containerClient = blobServiceClient.getBlobContainerClient(containerName);

System.out.println("Blobs in container:");
for (BlobItem blobItem : containerClient.listBlobs()) {
    System.out.println(" - " + blobItem.getName());
}