通过 Java 中的 API 下载 Azure Blob 文件

Question

我正在尝试用 Java 发布一个 API，以从 Azure blob 下载文件（如果存在），但在 openQueryInputStream 处出现异常。

BlobClient blobClient = blobContainerClient.getBlobClient(fileQueuePath + "/" + fileName);
            boolean blobExists = blobClient.exists();
            if (!blobExists) {
                     return Response.status(Response.Status.NOT_FOUND)
                        .entity("File not available in the specified path.")
                        .build();
            }

            InputStream is = blobClient.openQueryInputStream();

            return Response.ok(is)
                    .header("content-disposition", "attachment; filename=\"" + fileName + "\"")
                    .build();

        }

Answer 1

我相信您实际上没有正确创建下载流。

您可能想尝试以下更改：

if (!blobExists) {
    return Response.status(Response.Status.NOT_FOUND)
        .entity("File not available in the specified path.")
        .build();
}
try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
    blobClient.downloadStream(outputStream);
    final byte[] = outputStream.toByteArray();
    ByteArrayInputStream inputStream = new 
    ByteArrayInputStream(bytes);
        ByteArrayResource resource = new ByteArrayResource(bytes);
    return Response.ok(outputStream)
                    .header("content-disposition", "attachment; filename=\"" + fileName + "\"")
                    .build();

} catch(IOException e) {
    // Do something with the exception?
}

如果您愿意，您可以使用

BlobInputStream

来执行相同操作：

try (BlobInputStream blobStream = blobClient.openInputStream()) {
    blobStream.read();
    // Now return this stream.
} catch (IOException e) {
    // DO something?
}