Appending variable values to filename/variable names in Java/c++

I was wondering if anyone could help me with a programming matter?

Basically, I am trying to create n ArrayLists in Java, which I would like to
include the construction for this within loops with an appropriate name. So I
will find what n is from a calculation and I will be using an ArrayList as I
will not know the size of the vectors until all calculations have been
performed.

To save me hard coding in the construction of such ArrayLists when I know the
number (n) that I will need I have been racking my brains to come up with a
neater solution. In the past I have seen someone using notation such as a % or
$ or something like this in c++ which can be used to append the value of a variable to
the end of a filename, or at least I think that was what it was doing. What I am
wondering is there any such way in Java to loop over n and appropriately name my
ArrayLists as name1, name2.....namen? Also, I think that I would need to access
them using a similar method.

Regards
Sarah