[Storage][Docs] Document BlobItem.isPrefix to indicate that it is set to true for a directory

[abhikt48]

We have requirement to read only blob from a given directory, not from sub directory.
At this moment, i found below check blobItem.getProperties() == null && blobItem.getName().endsWith("/") to identify sub directory/folder.

Is this correct way to check sub directory/folder or Do we have any better way to check ? I tried to exclude subdirectory from listBlobsByHierarchy, but I didn't found any option yet.

Could you please suggest your opinion on this.

Iterator<BlobItem> iteratorBlobItem = getBlobContainerClient().listBlobsByHierarchy("test/").iterator();

while(iteratorBlobItem.hasNext()) {
	BlobItem blobItem = iteratorBlobItem.next();
	
	if(blobItem.getProperties() == null && blobItem.getName().endsWith("/")) {
		LOGGER.info("** it's directory '{}', do nothing **", blobItem.getName());
	}else {
		LOGGER.info("** it's blob '{}', create client abd start downloading **", blobItem.getName());
	}
}

• Version of the Library used - azure-storage-blob-12.10

[gapra-msft]

Hi @abhikt48

Thanks for your question. I believe BlobItem has an isPrefix property that indicates whether the blob is a prefix for another blob.

[abhikt48]

HI @gapra-msft - Thanks for quick reply.

I compared isPrefix value of Sub Directory and blob. Based on testing, can I assume that -

1. every sub directory will have isPrefix=true value.
2. blob file wil have isPrefix=null value
   Could you please confirm this ?

Please find below screen shot -

1. BlobItem of Sub-Directory
   

2. BlobItem of blob
   

[gapra-msft]

Yes that is correct.

[abhikt48]

Thanks for confirmation.

[abhikt48]

One suggestion- is possible for you to update JAVA documentation for isPrefix() - which will tell us that prefix used for sub-directory for folder identification. It will be very helpful for user. Please suggest your opinion.

[gapra-msft]

Yes! We can do that. Thank you for the suggestion. I will rename this issue appropriately