【Azure Developer】VS Code运行Java 版Azure Storage SDK操作Blob (新建Container, 上传Blob文件，下载及清理)

问题描述

是否可以用Java代码来管理Azure blob？可以。在代码中加入azure-storage-blob依赖。即可使用以下类操作Azure Storage Blob。

BlobServiceClient：BlobServiceClient 类可用于操纵 Azure 存储资源和 blob 容器。存储帐户为 Blob 服务提供顶级命名空间。
BlobServiceClientBuilder：BlobServiceClientBuilder 类提供流畅的生成器 API，以帮助对 BlobServiceClient 对象的配置和实例化。
BlobContainerClient：BlobContainerClient 类可用于操纵 Azure 存储容器及其 blob。
BlobClient：BlobClient 类可用于操纵 Azure 存储 blob。
BlobItem：BlobItem 类表示从对 listBlobs 的调用返回的单个 blob。

执行步骤

首先，设置VS Code上执行Java 代码的环境，这里需要的步骤比较多。完全参考VS Code for Java文档即可：https://code.visualstudio.com/docs/java/java-tutorial.

以下是创建项目步骤：

1）创建blob-quickstart-v12项目

【Azure Developer】VS Code运行Java 版Azure Storage SDK操作Blob (新建Container, 上传Blob文件，下载及清理)-LMLPHP

跳转到blob-quickstart-v12目录，并在目录中创建一个data目录，用于在接下来的代码中创建本地文件及下载bolb中的文件

cd blob-quickstart-v12

mkdir data

2) 修改pom.xml，添加对Java azure-storage-blob SDK的依赖

  <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代码文件中添加引用

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）添加Stroage Account的连接字符串

【Azure Developer】VS Code运行Java 版Azure Storage SDK操作Blob (新建Container, 上传Blob文件，下载及清理)-LMLPHP

5）创建blobServiceClient对象，同时调用createBlobContainer方法创建容器

        // 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）创建BlobClient对象，同时调用uploadFromFile方法上传文件(.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对象的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对象的downloadToFile方法下载文件到本地

        // 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对象的delete方法删除容器

        // 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中调试或执行，右键选择Run/Debug

【Azure Developer】VS Code运行Java 版Azure Storage SDK操作Blob (新建Container, 上传Blob文件，下载及清理)-LMLPHP

全部代码

App.java文件

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文件

<?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>

参考资料

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

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

路边两盏灯