Google's attorney emphasized that virtual machines have been around since the 1960s, and that Sun's Java Virtual machine didn't appear until 1994. Google views the inventions in Oracle's patents as "efficiency improvements" to Java and "very incremental inventions," he said, rather than central to the Java model.

The two sides also disagree how the patents should be interpreted. For instance, the so-called '104 patent states: "A method and apparatus for generating executable code and resolving data references in the generated code is disclosed."

Google considers that "resolving" the code requires rewriting it, while Oracle disagrees, Weingaertner said. The interpretation may play a role in determining whether Google is determined to have violated the patent.

The other patents discussed Wednesday are the '702 patent, which describes a method for stripping out redundant class files to make the final code run faster; and the '520 patent, a method for simulating how code will run before it actually runs, then producing more concise code to perform the actual operation.

The two sides also disagree about the extent to which Google forces handset makers to conform to its Android source code. Weingaertner said handset vendors are free to modify the code however they wish. "People can do what they want with it," the Google attorney said.