【Azure Developer】VS Code執行Java 版Azure Storage SDK操作Blob (新建Container, 上傳Blob檔案，下載及清理)

路邊兩盞燈發表於2020-12-09

DeveloperJavaAI

問題描述

是否可以用Java程式碼來管理Azure blob？可以。在程式碼中加入azure-storage-blob依賴。即可使用以下類操作Azure Storage Blob。

BlobServiceClient：BlobServiceClient 類可用於操縱 Azure 儲存資源和 blob 容器。儲存帳戶為 Blob 服務提供頂級名稱空間。
BlobServiceClientBuilder：BlobServiceClientBuilder 類提供流暢的生成器 API，以幫助對 BlobServiceClient 物件的配置和例項化。
BlobContainerClient：BlobContainerClient 類可用於操縱 Azure 儲存容器及其 blob。
BlobClient：BlobClient 類可用於操縱 Azure 儲存 blob。
BlobItem：BlobItem 類表示從對 listBlobs 的呼叫返回的單個 blob。

執行步驟

首先，設定VS Code上執行Java 程式碼的環境，這裡需要的步驟比較多。完全參考VS Code for Java文件即可：https://code.visualstudio.com/docs/java/java-tutorial.

以下是建立專案步驟：

1）建立blob-quickstart-v12專案

【Azure Developer】VS Code執行Java 版Azure Storage SDK操作Blob (新建Container, 上傳Blob檔案，下載及清理)

跳轉到blob-quickstart-v12目錄，並在目錄中建立一個data目錄，用於在接下來的程式碼中建立本地檔案及下載bolb中的檔案

cd blob-quickstart-v12

mkdir data

2) 修改pom.xml，新增對Java azure-storage-blob SDK的依賴

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.azure</groupId>
      <artifactId>azure-storage-blob</artifactId>
      <version>12.6.0</version>
  </dependency>
  </dependencies>

3）在App.java程式碼檔案中新增引用

package com.blobs.quickstart;

/**
 * Azure blob storage v12 SDK quickstart
 */
import com.azure.storage.blob.*;
import com.azure.storage.blob.models.*;
import java.io.*;

public class App
{
    public static void main( String[] args ) throws IOException
    {
        System.out.println("Azure Blob storage v12 - Java quickstart sample\n");

4）新增Stroage Account的連線字串

【Azure Developer】VS Code執行Java 版Azure Storage SDK操作Blob (新建Container, 上傳Blob檔案，下載及清理)

5）建立blobServiceClient物件，同時呼叫createBlobContainer方法建立容器

        // Create a BlobServiceClient object which will be used to create a container client
        BlobServiceClient blobServiceClient = new BlobServiceClientBuilder().connectionString(connectStr).buildClient();

        //Create a unique name for the container
        String containerName = "quickstartblobs" + java.util.UUID.randomUUID();

        // Create the container and return a container client object
        BlobContainerClient containerClient = blobServiceClient.createBlobContainer(containerName);

6）建立BlobClient物件，同時呼叫uploadFromFile方法上傳檔案(.tx)

        // Create a local file in the ./data/ directory for uploading and downloading
        String localPath = "./data/";
        String fileName = "quickstart" + java.util.UUID.randomUUID() + ".txt";
        File localFile = new File(localPath + fileName);

        // Write text to the file
        FileWriter writer = new FileWriter(localPath + fileName, true);
        writer.write("Hello, World!");
        writer.close();

        // Get a reference to a blob
        BlobClient blobClient = containerClient.getBlobClient(fileName);

        System.out.println("\nUploading to Blob storage as blob:\n\t" + blobClient.getBlobUrl());

        // Upload the blob
        blobClient.uploadFromFile(localPath + fileName);

7）使用containerClient物件的listBlobs方法列出容器中的BlobItem

        System.out.println("\nListing blobs...");

        // List the blob(s) in the container.
        for (BlobItem blobItem : containerClient.listBlobs()) {
            System.out.println("\t" + blobItem.getName());
        }

8）使用blobClient物件的downloadToFile方法下載檔案到本地

        // Download the blob to a local file
        // Append the string "DOWNLOAD" before the .txt extension so that you can see both files.
        String downloadFileName = fileName.replace(".txt", "DOWNLOAD.txt");
        File downloadedFile = new File(localPath + downloadFileName);

        System.out.println("\nDownloading blob to\n\t " + localPath + downloadFileName);

        blobClient.downloadToFile(localPath + downloadFileName);

9）使用containerClient物件的delete方法刪除容器

        // Clean up
        System.out.println("\nPress the Enter key to begin clean up");
        System.console().readLine();

        System.out.println("Deleting blob container...");
        containerClient.delete();

        System.out.println("Deleting the local source and downloaded files...");
        localFile.delete();
        downloadedFile.delete();

        System.out.println("Done");

10）在VS Code中除錯或執行，右鍵選擇Run/Debug

【Azure Developer】VS Code執行Java 版Azure Storage SDK操作Blob (新建Container, 上傳Blob檔案，下載及清理)

全部程式碼

App.java檔案

package com.blobs.quickstart;

/**
 * Azure blob storage v12 SDK quickstart
 */
import com.azure.storage.blob.*;
import com.azure.storage.blob.models.*;
import java.io.*;

public class App
{
    public static void main( String[] args ) throws IOException
    {
        System.out.println("Azure Blob storage v12 - Java quickstart sample\n");

        // 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 AZURE_STORAGE_CONNECTION_STRING. If the environment variable
        // is created after the application is launched in a console or with
        // Visual Studio, the shell or application needs to be closed and reloaded
        // to take the environment variable into account.
        String connectStr ="DefaultEndpointsProtocol=https;AccountName=xxxxxxxx;AccountKey=xxxxxxxxxxxxxxx;EndpointSuffix=core.chinacloudapi.cn";// System.getenv("AZURE_STORAGE_CONNECTION_STRING");

        // Create a BlobServiceClient object which will be used to create a container client
        BlobServiceClient blobServiceClient = new BlobServiceClientBuilder().connectionString(connectStr).buildClient();

        //Create a unique name for the container
        String containerName = "quickstartblobs" + java.util.UUID.randomUUID();

        // Create the container and return a container client object
        BlobContainerClient containerClient = blobServiceClient.createBlobContainer(containerName);

        // Create a local file in the ./data/ directory for uploading and downloading
        String localPath = "./data/";
        String fileName = "quickstart" + java.util.UUID.randomUUID() + ".txt";
        File localFile = new File(localPath + fileName);

        // Write text to the file
        FileWriter writer = new FileWriter(localPath + fileName, true);
        writer.write("Hello, World!");
        writer.close();

        // Get a reference to a blob
        BlobClient blobClient = containerClient.getBlobClient(fileName);

        System.out.println("\nUploading to Blob storage as blob:\n\t" + blobClient.getBlobUrl());

        // Upload the blob
        blobClient.uploadFromFile(localPath + fileName);

        System.out.println("\nListing blobs...");

        // List the blob(s) in the container.
        for (BlobItem blobItem : containerClient.listBlobs()) {
            System.out.println("\t" + blobItem.getName());
        }

        // Download the blob to a local file
        // Append the string "DOWNLOAD" before the .txt extension so that you can see both files.
        String downloadFileName = fileName.replace(".txt", "DOWNLOAD.txt");
        File downloadedFile = new File(localPath + downloadFileName);

        System.out.println("\nDownloading blob to\n\t " + localPath + downloadFileName);

        blobClient.downloadToFile(localPath + downloadFileName);

        // Clean up
        System.out.println("\nPress the Enter key to begin clean up");
        System.console().readLine();

        System.out.println("Deleting blob container...");
        containerClient.delete();

        System.out.println("Deleting the local source and downloaded files...");
        localFile.delete();
        downloadedFile.delete();

        System.out.println("Done");
    }
}

pom.xml檔案

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.blobs.quickstart</groupId>
  <artifactId>blob-quickstart-v12</artifactId>
  <version>1.0-SNAPSHOT</version>

  <name>blob-quickstart-v12</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.azure</groupId>
      <artifactId>azure-storage-blob</artifactId>
      <version>12.6.0</version>
  </dependency>
  </dependencies>

  <build>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-jar-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
        <plugin>
          <artifactId>maven-site-plugin</artifactId>
          <version>3.7.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-project-info-reports-plugin</artifactId>
          <version>3.0.0</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

參考資料

Getting Started with Java in VS Code：https://code.visualstudio.com/docs/java/java-tutorial

快速入門：使用 Java v12 SDK 管理 blob: https://docs.azure.cn/zh-cn/storage/blobs/storage-quickstart-blobs-java#code-examples

【Azure Developer】VS Code執行Java 版Azure Storage SDK操作Blob (新建Container, 上傳Blob檔案，下載及清理)

問題描述

執行步驟

全部程式碼

參考資料

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