From http://www.wikihow.com/Install-Oracle-Java-on-Ubuntu-Linux
Type/Copy/Paste: java -version . If you're having
OpenJDK Runtime Environment (IcedTea6 1.10pre) (7b15~pre1-0lucid1)
OpenJDK 64-Bit Server VM (build 19.0-b09, mixed mode)
... you have the wrong vendor version of Java installed for this exercise.
This is what I have. I wonder, why is this a wrong vendor? What is this vendor? Why should I use Oracle Java instead?