[BUG] getMetadata returns only nulls

[MichaelVonB]

Describe the bug
We upload blob with metaData and query them later. However the metadata always return null even tough I can see them in the azure portal.

Exception or Stack Trace
n/a

To Reproduce
see code below

Code Snippet

BlobParallelUploadOptions options =
            new BlobParallelUploadOptions(byteArrayInputStream)
                .setRequestConditions(new BlobRequestConditions().setIfNoneMatch(Constants.HeaderConstants.ETAG_WILDCARD)) // sets overwrite files to false
                .setMetadata(Map.of("foo", "bar"))
                .setHeaders(jsonHeaders);

blobClient.uploadWithResponse(options, null, Context.NONE);

and query them later on essentially like this

BlobContainerClient blobContainerClient = blobServiceClient.getBlobContainerClient("my-blob-container-client");
List<Map<String, String>> metaDataList = blobContainerClient.listBlobs().stream()
            .map(BlobItem::getMetadata)
            .toList();

But this will be a List of nulls. However I can see in the azure portal that the meta data is filled.
This works but I would expect the other solution to work aswell

List<Map<String, String>> metaDataListFull = blobContainerClient.listBlobs().stream()
            .map(it -> blobContainerClient.getBlobClient(it.getName()))
            .map(it -> it.getProperties().getMetadata())
            .toList();

Add the code snippet that causes the issue.

Expected behavior
I would expect BlobItem::getMetadata to return the metadata and not null.

Screenshots
n/a

Setup (please complete the following information):

• OS: macOS / OpenShift
• IDE: IntelliJ / -
• Library/Libraries: azure-storage-blob-12.25.1
• Java version 17
• App Server/Environment: Tomcat
• Frameworks:Spring Boot

[alzimmermsft]

Thanks for filing this issue @MichaelVonB.

I believe you're running into this problem as there aren't any includes set in the listBlobs call. This document goes over the REST API details on how to include additional information in the response BlobItem:

https://learn.microsoft.com/rest/api/storageservices/list-blobs?tabs=microsoft-entra-id#metadata-in-the-response

And here is an example of the updated Java code:

BlobContainerClient blobContainerClient = blobServiceClient.getBlobContainerClient("my-blob-container-client");
List<Map<String, String>> metaDataList = blobContainerClient.listBlobs(new ListBlobsOptions().setDetails(new BlobListDetails().setRetrieveMetadata(true)), null).stream()
            .map(BlobItem::getMetadata)
            .toList();

And here is a test we run that validates the behavior:

https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/storage/azure-storage-blob/src/test/java/com/azure/storage/blob/ContainerApiTests.java#L819

[MichaelVonB]

Thank you for your quick supply. This fixed the issue. My bad i missed this.
For local development we are using azurite and there metadata are always populated regardless of ListBlobsOptions so we never searched in that direction.