We are facing a little inconsistency concerning the attachment id.
In the REST API the attachment IDs have the form “att12345678”.
In the Confluence Server JAVA API the attachment IDs have the form “12345678”.
Removing/Adding the “att” prefix is an obvious workaround, but I wonder if there is another way to solve this inconsistency (another API?) without assuming any naming convention that could be broken in the future.