将包含空子文件夹的文件夹上传到S3（使用AWS Java SDK）

Question

I try to upload a folder from my locale laptop to Amazon's S3. I use the following code with Amazon's Java SDK:

File folder = new File("c:/some/of/my/folders");
TransferManager tm = new TransferManager( AWS.getAwsCredentials() );
MultipleFileUpload upload = tm.uploadDirectory( "my-bucket", folder.getName(), folder, true );
upload.waitForCompletion();
tm.shutdownNow();

The actual upload works as expected and I can see my folder, subfolders and files on the web console of S3. But all empty folders (which contain no files or other folders) are missing. How can I upload them to?

I know that S3 doesn't know "folders" and works with keys since it is no file system. But I can create "a folder" by uploading empty content (eg like here ). As far as I can see, the only solution for my problem would be to upload the folder like shown above and then iterate trough my folder looking for all empty folders and uploading them separately. Any other ideas?

Answer 1

You are right, s3 is a key-object map (not hierarchical). Creating an empty (0 byte) object with a key ending in "/" should display in the S3 Management Console as a folder.