The Oracle-Google copyright showdown is now in the hands of a San Francisco jury, following heated closing arguments given today to a packed courtroom. It's the culmination of the most high-profile attack on Google's Android mobile operating system, which Oracle lawyers say illegally ripped off Java.

In closing today, Oracle lawyer Michael Jacobs said that Google knowingly structured its Android APIs in the same way that Java APIs were structured, even though it knew that move was legally dicey; Google's lawyer, meanwhile, emphasized Android's originality and the fact that Sun Microsystems, which invented Java, had only good things to say about Android, even encouraging Google.

In addition to arguing that it didn't infringe Sun's copyrights at all, Google argued any use it did make should be considered "fair use." Jacobs ridiculed the fair use argument, saying it was merely Google's "first excuse."

The deliberations now underway are the first phase of Oracle America Inc. v. Google Inc., a trial between two tech heavyweights being played out in San Francisco federal court. The whole trial will last about eight weeks, and the copyright case is just the first "phase." The verdict, likely to come later this week, will be the first indication of how the jury views the evidence.

Oracle's claim: "There's a new sheriff in town."

Android doesn't have the same computer code that's in Java, but Oracle argues that because Google closely followed the "structure, sequence, and organization" of 37 Java Application Program Interfaces, or APIs, its copyrights have been violated. (Oracle acquired copyrights and patents associated with the Java language when it purchased Sun Microsystems in 2010.)

Judge William Alsup is letting several copyright questions go to the jury, even though the judge himself could still decide that APIs aren't copyrightable at all, and are just sets of instructions.

For the purposes of this case, the jurors were told to assume that APIs are indeed protectable. Oracle's lawyer, Michael Jacobs, made his case during closings that the Java APIs were "complex, creative, and artful," and that the 37 APIs Google had imitated were some of the "crown jewels" of the Java system. And that makes Google's copying a big deal—tantamount to using Oracle property without permission.

"This is not trivial," said Jacobs at one point. "This is very substantial copying that Google engaged in."

And Google's e-mails show that it knew a lawsuit was a real risk, he argued. That copying had damaged the Java community, and by giving away Android for free Google had "fragmented" the developer community—and made it hard for others to compete. "How do you compete with free in the smartphone world?" asked Jacobs, echoing a point that Oracle CFO Safra Catz made last week. "This harm to Java is on all levels."

As for ex-Sun CEO Jonathan Schwartz's blog post welcoming the launch of Android, which has been touted by Google lawyers as proof that Sun approved of Google's actions, Jacobs said Schwartz was simply someone who didn't have a choice about Google's use of Java. "A blog post is not permission," said Jacobs. "A blog post is not a license." He portrayed Schwartz as someone who simply had no choice, highlighting Schwartz's testimony that he "grit [his] teeth," and was trying to "make the best of an uncomfortable situation."

In any case, the fact that Sun chose not to be aggressive about its intellectual property isn't relevant. "There is a new sheriff in town," Jacobs told the jury. "There is more investment in Java; there are more resources being devoted. The layoffs have stopped. [Now] we need the help of the justice system to enforce our intellectual property rights."

Google's defense: "They're not even in the ballpark."

The best argument that Google didn't do anything wrong was Sun's own reaction to Android at the time, said Google defense lawyer Robert Van Nest. Schwartz and others at Sun praised Google and even asked about how it could use Android, Van Nest said; and Schwartz confirmed what folks at Google thought, that the APIs are an intrinsic, inseparable part of the Java language, which is free for all to use.

Oracle is "not even in the ballpark" when it comes to proving similarities between the 37 Java APIs it claims ownership of, and Android's own APIs. And, he emphasized, Oracle isn't accusing Google of copying code—because it can't. After designing a computer program to analyze Android's millions of lines of code, Oracle found only nine lines of copied code in a function called rangeCheck() . That code, accidentally inserted by a Google engineer who testified last week, has been removed from all current versions of Android. "Other than the nine lines of code in rangecheck, everything in Android is original," said Van Nest—created entirely by Google engineers, or with Apache open source code.

As to Oracle's claim about the "structure, sequence, and organization" of the programming, Van Nest claimed since Oracle lacked evidence of true copying, it came around to the idea of "structure, sequence and organization"—a concept that Van Nest said was "something made up for this lawsuit," and was never fathomed by anyone at Sun or Google during their negotiations over Android and Java.

While Van Nest made it clear to jurors he thought Google should be in the clear on the primary question—and that it doesn't infringe copyrights at all—he presented a second defense as well. Because Android was transformative, APIs are "functional" tools, and Android didn't hurt the market for Java—profits in Oracle's Java-related businesses were up about 10 percent last year—any Android use of a copyrighted work should be found "fair use," in any case, Van Nest argued.

The jury is out

In their verdict form, the jury has to decide three essential questions: first, whether Google was infringing copyrights of the Java APIs; whether Google's use of the copyrighted material should be considered "fair use;" and a third question about whether the conceded small amount of actually copied code in Android is significant or "de minimis." A fourth question about whether Google could have reasonably believed it did not need a license is marked as being an advisory one for the judge that doesn't bear on the main questions.

On Monday, the jury left about an hour-and-a-half after closing arguments concluded. The panel of 12 will return tomorrow morning, and a verdict could come any time after that.