ArrayList question.....

Hey everyone!!

I found this community because I am in some desperate need of Java help.

I'm writing a program that simulates a computer's allocation of memory through the algorithms of first fit, best fit, and worst fit. My proble though, lies within ArrayLists. I haven't used ArrayLists in awhile, and when I did, it was just for one simple Intro to Java program. So I know how to use the methods and such. However, what I am trying to do is put an object, Holes, that I have created in the ArrayList, and then invoke various methods of the Holes objects that I create. Going through the ArrayLists methods this is what I thought would work:

//Where each "size" is a different randomly genrated number
Holes hole1 = new Holes(size);
Holes hole2 = new Holes(size);
ArrayList mem = new ArrayList();

mem.add(0,hole1);
mem.add(1,hole2);

//Where "getSize()" is a method in my Holes class that just returns the value
//of the passed size of the hole
System.out.println(mem.get(0).getSize());
System.out.orintln(mem.get(1).getSize());


So why will this not display the two different sizes? Researching the various ArrayList methods, it said that "get(int)" returns an object, so why can't I invoke its method?

I hope that was clear enough! :)

Cheers!
RM