They copied the API interfaces. I'm sure every developer has done the same a multitude of times. If you want to talk to the same REST API using the same client, you've probably written an exact copy of the code a bunch of others have written.
Computer science reverse engineering often means recreating the same code, maybe even line by line. Allowing anyone to copyright an API would break the internet.
Imagine writing quicksort in a popular language as an excercise. Usually there's only a few straightforward ways to do it, so the same code has been written tons of times. If the original writer had copywrite, nobody could use quicksort.
Correct me if I'm wrong, but my understanding of copyright is that if you come up with something independently you're not violating copyright. So if you and I both write code to interact with the same REST API and end up writing identical code, there's no violation.
But Google didn't just coincidentally happen to match the Java api; they intentionally copied the method signatures then reimplemented the methods. The issue at hand is copying all the method signatures, not reimplementing the methods. I don't know whether that is or should be a copyright violation or not, but it's different from what you described in your comment.
Not really, the interface signatures need to be the same for normal Java code to work. There's only one way to write the interfaces, code would be identical even reverse engineered.
This is the same as writing an S3 compatible java client. If you want to be able to substitute one directly for another, the method signatures have to be the same even if all the implementations are different.
This also mirrors how kernel interfaces work. Xen, GVisor, and many others implement the exact same kernel interfaces as Linux because they have to to work. If the API was copyrightable any contributor that designed one of these interfaces could prevent these projects from existing
But what would have been the solution? They could have just made it ToString_Google() and HashMap_Google. This is so far beyond anyone actually having their rights impinged upon at this point that the only winner to this whole thing can be the lawyers making money hand over fist.
Computer science reverse engineering often means recreating the same code, maybe even line by line. Allowing anyone to copyright an API would break the internet.
Imagine writing quicksort in a popular language as an excercise. Usually there's only a few straightforward ways to do it, so the same code has been written tons of times. If the original writer had copywrite, nobody could use quicksort.