Rename filename on S3 using S3Client

I try to rename filename on AWS drive. My connection with AWS is configured. I prepared a piece of code that should copy new file with changed filename, but it copies file with unchanged filename.

void updateFileName(String key, String newKey, String newName) {
    CopyObjectRequest copyReq = CopyObjectRequest.builder()
            .copySource(bucket + "/" + key)
            .destinationBucket(bucket)
            .destinationKey(newKey)
            .contentDisposition("attachment; filename=" + newName)
            .build();

    s3Client.copyObject(copyReq);
}

I found the solution. In the builder of CopyObjectRequest I added .metadataDirective(MetadataDirective.REPLACE). The code should look like:

void updateFileName(String key, String newKey, String newName) {
CopyObjectRequest copyReq = CopyObjectRequest.builder()
        .copySource(bucket + "/" + key)
        .destinationBucket(bucket)
        .destinationKey(newKey)
        .contentDisposition("attachment; filename=" + newName)
        .metadataDirective(MetadataDirective.REPLACE)
        .build();

s3Client.copyObject(copyReq);}

The official AWS Docs have a section called "Copy, Move, or Rename Objects" that you can find here.

It states:
> You can copy an object from one bucket to another by using the AmazonS3 client’s copyObject method. It takes the name of the bucket to copy from, the object to copy, and the destination bucket name.

The relevant piece of code for you is this:

s3.copyObject(from_bucket, object_key, to_bucket, object_key);

You can also find a full example on GitHub here.

Something to note, on AWS S3 the concepts of update/rename/move an object don't really apply. SDKs and other higher level libraries might expose APIs that allow to perform such operations but at the end of the day you're either rewriting the same object in case of an update or writing a new one and deleting the old one in case of rename/move.

This is also explained in a note in the same page I linked above:
> You can use copyObject with deleteObject to move or rename an object, by first copying the object to a new name (you can use the same bucket as both the source and destination) and then deleting the object from its old location.