import java.util.List; import java.util.stream.Stream; import java.util.stream.Collectors; public class Test{ public static void main(String...s){ List<String> collected = Stream.of("a","b","c").collect(Collectors.toList()); List<String> upperCaseList = collected.stream().map(e->e.toUpperCase()).collect(Collectors.toList()); System.out.println(upperCaseList); } }