Efficient way to divide a list into lists of n size

Question

I have an ArrayList, which I want to divide into smaller Lists of n size, and perform an operation on each. My current method of doing this is

implemented with Array

Answer 1

You'll want to do something that makes use of List.subList(int, int) views rather than copying each sublist. To do this really easily, use Guava's Lists.partition(List, int) method:

List foos = ...
for (List partition : Lists.partition(foos, n)) {
  // do something with partition
}

Note that this, like many things, isn't very efficient with a List that isn't RandomAccess (such as a LinkedList).