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
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
junit
junit
4.11
test
com.azure
azure-storage-blob
12.6.0
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
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
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
7）使用containerClient对象的listBlobs方法列出容器中的BlobItem
);
// 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
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
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0
com.blobs.quickstart
blob-quickstart-v12
1.0-SNAPSHOT
blob-quickstart-v12
http://www.example.com
UTF-8
1.7
1.7
junit
junit
4.11
test
com.azure
azure-storage-blob
12.6.0
maven-clean-plugin
3.1.0
maven-resources-plugin
3.0.2
maven-compiler-plugin
3.8.0
maven-surefire-plugin
2.22.1
maven-jar-plugin
3.0.2
maven-install-plugin
2.5.2
maven-deploy-plugin
2.8.2
maven-site-plugin
3.7.1
maven-project-info-reports-plugin
3.0.0
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
