Remember long time ago, I ever saw a post talking about the refrence of Java. But with the passing of time, almost forget it compeltely. Recently, I looked at another post on the server side agruing the pass by reference. I have to reread it and make it much deeper in my mind. The follow artcile is a good one for pass by reference - http://javadude.com/articles/passbyvalue.htm.
Primitives are passed by value
Objects are passed reference by value (call by sharing)