import java.util.List;import java.util.ArrayList;import java.util.Collection;import java.util.Iterator;public class ejer_3{public static void main(String[] arg){char[] vocales = {'a','e','i','o','u'};List lista = new ArrayList();for (char vocal : vocales) lista.add(vocal); imprimirVocales(lista); }public static void imprimir(Collection coleccion){Iterator iterator = coleccion.iterator();while (iterator.hasNext()){System.out.println(iterator.next());}}}import java.util.List;import java.util.ArrayList;import java.util.Collection;import java.util.Iterator;import java.util.List;import java.util.LinkedList;import java.util.ListIterator;public class ejer_4{public static void main(String[] arg){String[] vocales = {"A","e","I","o","U"};List lista = new ArrayList();for (String vocal : vocales) lista.add(vocal); imprimir(lista);minusculas(lista);imprimir(lista); }public static void imprimir(Collection coleccion){Iterator iterator = coleccion.iterator();while (iterator.hasNext()){System.out.print(iterator.next()+ " " );}System.out.println("");}public static void minusculas(List lista){ListIterator iterador = lista.listIterator();while (iterador.hasNext()){String vocal = iterador.next();iterador.set(vocal.toLowerCase()); }}}