Hi there. I want to install OpenOffice onto my newer Retina running Sierra, and possibly LibreOffice. I believe one or both require Java. And so I have some questions... 1.) How do I tell if I have Java on my Mac? 2.) How do I tell which version of Java I have? 3.) Is it true that Oracle now requires you to register with them in order to download Java? 4.) How do I tell if I have Java SE or the JRE installed on my Mac? 5.) How do I upgrade Java on my Mac? 6.) I thought that Java was considered a "security risk"? Is this true? Thanks!