S3 ACL request owner display name sometimes returns null

[dmytro-sylaiev]

Describe the bug

I got the issue with retrieving the acl response Owner displayName. Sometimes it returns null, sometimes not.

When execute this code:

`private static S3Client s3Client;

public static void main(String[] args) {
    s3Client = S3Client.builder()
            .accelerate(false)
            .region(Region.AP_SOUTHEAST_2)
            .crossRegionAccessEnabled(true)
            .credentialsProvider(StaticCredentialsProvider.create(AwsBasicCredentials.create(getAccessKeyId(),
                    getSecretAccessKey())))
            .build();


    for (int i = 0 ; i< 10; i++) {
        System.out.println(getOwner(getBucketName(), getItemName()).displayName());
    }
}

public static Owner getOwner(String bucketName, String key) {
    GetObjectAclRequest aclRequest = GetObjectAclRequest.builder()
            .bucket(bucketName)
            .key(key)
            .build();

    GetObjectAclResponse aclResponse = s3Client.getObjectAcl(aclRequest);
    return aclResponse.owner();
}`

using amazon-s3-encryption-client-java:3.4.0 I got that response:

null
null
Real owner display name
Real owner display name
Real owner display name
null
Real owner display name
Real owner display name
Real owner display name
Real owner display name

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

ACL response contains Owner display name every time

Current Behavior

Randomly s3Client.getObjectAcl(aclRequest).owner().displayName() returns null

Reproduction Steps

Execute code from the description (increase the counter in the loop if needed)

Possible Solution

No response

Additional Information/Context

No response

AWS Java SDK version used

2.31.62 and 2.34.8

JDK version used

openjdk 17.0.9 2023-10-17 LTS

Operating System and version

Windows 11

[debora-ito]

There's an important notice about DisplayName in the GetObjectAcl API Reference, quote:

End of support notice: Beginning November 21, 2025, Amazon S3 will stop returning DisplayName. Update your applications to use canonical IDs (unique identifier for AWS accounts), AWS account ID (12 digit identifier) or IAM ARNs (full resource naming) as a direct replacement of DisplayName.

Between July 15, 2025 and November 21, 2025, you will begin to see an increasing rate of missing DisplayName in the Owner object.

This change affects the following AWS Regions: US East (N. Virginia) Region, US West (N. California) Region, US West (Oregon) Region, Asia Pacific (Singapore) Region, Asia Pacific (Sydney) Region, Asia Pacific (Tokyo) Region, Europe (Ireland) Region, and South America (São Paulo) Region.

So this not a bug, S3 will stop returning DisplayName.

[afranken]

@debora-ito looking at AWS API docs, DisplayName is now gone from most APIs, at least for the Owner data structure, e.g. https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetBucketAcl.html

The notices disappeared, BTW.

But the data structure itself still lists DisplayName: https://docs.aws.amazon.com/AmazonS3/latest/API/API_Owner.html

Is there a plan to remove displayName functions for requests and responses still available in this AWS SDK or at least add a deprecation notice? e.g., software.amazon.awssdk.services.s3.model.Owner#displayName still exists in the current versions and is not even deprecated.