Can I cast an object read from a file - after serialization - to a Collection of my own objects ?

Question

When I try to do that it shows me a warning saying that this cast is unchecked.

Answer 1

this is for Collection of Strings

Collection<String> col1 = new ArrayList<>(
List.of("aa","bb","cc") );
Object object = col1;

Collection<String> col2 =
new ArrayList<String>();
if (object instanceof Collection ) {
((Collection<?>) object).forEach(o -> {
if (o instanceof String)
col2.add( (String) o ); });
}
System.out.println(col2);