如何在 Azure blob 下载中获取 blob 下载进度

Question

我想从 Azure blob 存储下载一个大尺寸的 blob。假设我的 blob 大小为 2 GB。我想使用java-sdk 以百分比形式获取下载进度，以便显示一些漂亮的进度条。我正在使用以下代码下载 blob

        BlobServiceClient blobServiceClient = new BlobServiceClientBuilder().connectionString("connectionString").buildClient();
        BlobContainerClient blobContainerClient = blobServiceClient.getBlobContainerClient("cloudDirectoryName");
        BlobClient blobClient = blobContainerClient.getBlobClient(fileName);

        BlobRange range = new BlobRange(1024, 2048L);
        DownloadRetryOptions options = new DownloadRetryOptions().setMaxRetryRequests(5);

        blobClient.downloadToFileWithResponse(filePath, null, new ParallelTransferOptions(4 * Constants.MB, null, null),
            options, null, false, null, null);

Answer 1

如果要获取下载进度，请参考以下代码

1. SDK

 <dependency>
      <groupId>com.azure</groupId>
      <artifactId>azure-storage-blob</artifactId>
      <version>12.7.0</version>
  </dependency>

1. 代码

public class App 
{
    public static void main( String[] args )
    {
        String accountName="blobstorage0516";
        String accountKey ="";
        StorageSharedKeyCredential creds = new StorageSharedKeyCredential(accountName,accountKey);

        String endpoint = String.format(Locale.ROOT, "https://%s.blob.core.windows.net", accountName);
        BlobServiceClient blobServiceClient =new BlobServiceClientBuilder()
                .endpoint(endpoint)
                .credential(creds)
                .buildClient();
        BlobContainerClient blobContainerClient  =blobServiceClient.getBlobContainerClient("image");
        BlobClient blobClient= blobContainerClient.getBlobClient("test.jpg");
        String filePath="D:\\test\\test.jpg";
       ProgressReceiver reporter = new FileDownloadReporter();
        ParallelTransferOptions options= new ParallelTransferOptions(4 * Constants.MB,null,reporter);
        Response<BlobProperties> repose= blobClient.downloadToFileWithResponse(filePath,new BlobRange(0),options,null,null,false, null,Context.NONE);
        System.out.println(repose.getStatusCode());


    }


}

class FileDownloadReporter implements ProgressReceiver {


    @Override
    public void reportProgress(long bytesTransferred) {
        System.out.println(String.format("You have download %d bytes", bytesTransferred));
    }
}