Dr Heinz Kabutz is a computer scientist who specializes in the Java Programming Language.  He is a Java Champion and a JavaOne Rock Star Speaker.  He has been teaching Java since 1999 to thousands of programmers in many different countries.  His primary focus is offering in-house courses to companies to teach professional Java programmers to be even more effective at their coding.  He is a regular speaker at conferences around the world, such as Devoxx, Voxxed Days, Java One, JAX and many JUG events.