It’s the ultimate recursion: Making Java with Java ;-)
Last year, Vinicus Senger already proved you could make Java (the hot one) with Java (the equally hot one), with his “Having Fun with Home Automation and Java EE” project. See this parleys.com video.
Now, Sasha Wolter created the next iteration. As part of a project for the Deutsche Telekom Developer Garden he built a voice-controlled coffee machine, using the Raspberry Pi, Oracle Java, a Nespresso machine, and some network APIs of Deutsche Telekom.