what is the difference between pass by reference and call by reference in java ?
You asked but, "pass by reference" and "call by reference" are same thing.
If you are looking for difference between pass by reference and pass by value check answers to
Pass by reference or pass by value?
But remember, Java passes parameter by value.
http://javadude.com/articles/passbyvalue.htm
http://academic.regis.edu/dbahr/GeneralPages/IntroToProgramming/JavaPassByValue.htm