Google is being sued by Oracle over claims that there are Java related copyright problems within Android.
Oracle sued Google, claiming the company "knowingly, directly and repeatedly infringed Oracle's Java-related intellectual property" in developing the Android platform.
At the time Google claimed that Oracle's case was unwarranted, given the fact that Java is open-source.
According to court documents Google's latest legal documents show several new lines of defences beyond the open-source argument.
These are that Google did not infringe on any patents, any way Oracle's patents and copyrights are invalid or unenforceable and Android is fair use of Oracle's IP.
Google's will also claim that Oracle's licensing practices for certain open-source technologies and technologies not actually covered by Oracle's IP.
The last line of defence is that if there had been "any use in the Android platform of any protected elements" of Java, Google itself "is not liable" due to the face that such violations would have been committed by third parties and without Google's knowledge.
While Java is open source, what appears to be the problem with Android is the Dalvik virtual machine which is part of the stack that actually executes code on Android devices.This is useful for mobile gear because they don't have as much memory to play with and their processors are less than half the power of a PC.
Oracle claims that it is this which violates the patents.