无需本地下载即可从Azure Blob容器中读取镶木地板数据

2022-05-11 00:00:00 azure parquet streaming java

我正在使用azure SDK、avro-parquet和Hadoop库从Blob Container中读取拼图文件。目前,我正在将文件下载到临时文件,然后创建一个ParquetReader。

try (InputStream input = blob.openInputStream()) {
                Path tmp = Files.createTempFile("tempFile", ".parquet");

                Files.copy(input, tmp, StandardCopyOption.REPLACE_EXISTING);
                IOUtils.closeQuietly(input);
                InputFile file = HadoopInputFile.fromPath(new org.apache.hadoop.fs.Path(tmp.toFile().getPath()),
                        new Configuration());
                ParquetReader<GenericRecord> reader = AvroParquetReader.<GenericRecord> builder(file).build();

                GenericRecord record;
                while ((record = reader.read()) != null) {
                    recordList.add(record);
                }
            } catch (IOException | StorageException e) {
                log.error(e.getMessage(), e);
            }

我想使用来自azure BLOB项的inputStream读取此文件,而无需将其下载到我的机器上。S3有这样的方法(Read parquet data from AWS s3 bucket),但Azure是否存在这种可能性?


解决方案

了解如何执行此操作。

 StorageCredentials credentials = new StorageCredentialsAccountAndKey(accountName, accountKey);
 CloudStorageAccount connection = new CloudStorageAccount(credentials, true);
 CloudBlobClient blobClient = connection.createCloudBlobClient();
 CloudBlobContainer container = blobClient.getContainerReference(containerName);

 CloudBlob blob = container.getBlockBlobReference(fileName);

 Configuration config = new Configuration();
 config.set("fs.azure", "org.apache.hadoop.fs.azure.NativeAzureFileSystem");
 config.set("fs.azure.sas.<containerName>.<accountName>.blob.core.windows.net", token);
 URI uri = new URI("wasbs://<containerName>@<accountName>.blob.core.windows.net/" + blob.getName());
 InputFile file = HadoopInputFile.fromPath(new org.apache.hadoop.fs.Path(uri),
                config);
 ParquetReader<GenericRecord> reader = AvroParquetReader.<GenericRecord> builder(file).build();

 GenericRecord record;
 while ((record = reader.read()) != null) {
     System.out.println(record);
 }
 reader.close();

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