Oracle is suing Google over the latter's Java implementation in Android. The question is, did Google develop its version of Java, called Dalvik, from the ground up without borrowing any code from Sun's Java, or did they infringe on Sun's intellectual property, now owned by Oracle?According to Gartner analyst Ken Dulaney, Google developed Dalvik in a "clean room" meaning no one on the Dalvik team had any internal knowledge of how Sun's Java was developed. This is what PC developers did a few decades ago when they came up with a BIOS that allow PC operating systems to run without infringing upon IBM's rights. By doing it that way, you don't have to pay the entity you are mimicking.
Oracle claims Java was one of the most valuable properties it acquired in the Sun acquisition. They are claiming Google violated seven of the patents that Oracle now owns.
A company certainly has a right to defend its ownership of intellectual property, but IP lawsuits today have made many, myself included, rather cynical about their legitimacy. I tend to think Oracle is wanting to cash in on Android's success. Android is, after all, probably one of the most successful consumer devices to use Java.
Unless a settlement is reached quickly, doubtful given Google's "Oh no we didn't!" response, it will be several years before there is a resolution and Google will be in the final stages of releasing Android 9.2, code named Tapioca by then.