Since Java 8, there are some standard options to do this in JDK:
Collection<E> in = ...
Object[] mapped = in.stream().map(e -> doMap(e)).toArray();
// or
List<E> mapped = in.stream().map(e -> doMap(e)).collect(Collectors.toList());
See java.util.Collection.stream()
and java.util.stream.Collectors.toList()
.