Question

My, perhaps naive, solution for cloning an ArrayList (Vector replacement) is

ArrayList<Double> alBis = (ArrayList<Double>) alOriginal.clone();

considering that because the array contains immutable Doubles, I don’t need
to clone them, but only the container.

As clone() returns an Object I put there the cast, but then
-Xlint complains it is an unchecked cast.

So, what now? Ignore it with supressWarnings? Create a new ArrayList
and copy the orginal elements with a compact for? Any library method similar to
Arrays.copyOf()?

I read Unchecked cast warning but the accepted way is incredible complex.

Answer 1

clone() has major flaws, see this Question for reference. Don’t use it!

Instead, all standard Collections have copy constructors. Use them:

List<Double> original = // some list
List<Double> copy = new ArrayList<Double>(original);

Reference:

• ArrayList<E>(Collection) constructor