After seeing the majority of its Java infringement claims against Android essentially sideways in 2012, Oracle has now won an important turnaround on appeal that will allow it to pursue its $1 billion case against Google and potentially an injunction against Android as infringing its Java intellectual property.

Sources revealed that the U.S. Court of Appeals for the Federal Circuit in Washington issued a ruling(69-page decision) on May 9 that reversed an earlier decision that prohibited Oracle from claiming copyright for portions of its Java platform used by Google in Android.

Google had argued in the original trial that Oracle’s Java wasn’t protected by copyright for a number of reasons, including the ideas that the code isn’t purely a creative expression; that it used short phrasing and that Google borrowed Java API code in order to maintain interoperability with Java. The initial court agreed.

Federal Circuit Judge Kathleen O’Malley wrote the opinion. Here’s the key quote, critiquing Judge Alsup’s ruling:

“We find that the district court failed to distinguish between the threshold question of what is copyrightable — which presents a low bar — and the scope of conduct that constitutes infringing activity. The court also erred by importing fair use principles, including interoperability concerns, into its copyrightability analysis. For the reasons that follow, we conclude that the declaring code and the structure, sequence, and organization of the 37 Java API packages are entitled to copyright protection.”

Following the ruling, Oracle issued a statement to the media saying, “We are extremely pleased that the Federal Circuit denied Google’s attempt to drastically limit copyright protection for computer code. The Federal Circuit’s opinion is a win for Oracle and the entire software industry that relies on copyright protection to fuel innovation and ensure that developers are rewarded for their breakthroughs. We are confident that the district court will appropriately apply the fair use doctrine on remand, which is not intended to protect naked commercial exploitation of copyrighted material.”

Google just issued the following statement: “We’re disappointed by this ruling, which sets a damaging precedent for computer science and software development, and are considering our options.”

In August, Oracle’s chief executive Larry Ellison stated, “When you write a program for the Android phone, you use the Oracle Java tools for everything. And then at the very end, you press a button and say, ‘Convert this to Android format.’ We don’t compete with Google. We don’t do anything Google does. We just think they took our stuff, and that was wrong.”

The case could have wider implications for the software industry. Some developers argued that making the APIs subject to copyright law would limit their ability to build compatible programs and would stifle innovation. Many big software vendors disagreed and said APIs are creative works that are worthy of protection.