Java Programs easy way

package java2;

import java.util.Arrays;

import java.util.List;

public class mettl37 {

      public static int output1;

      public static void fn(String s) {

            int count = 0;

            for (int i = 0; i < s.length(); i++) {

                  String[] s4 = { "a", "e", "i", "o", "u", "A", "E", "I", "O", "U" };

                  List<String> l1 = Arrays.asList(s4);

                  if (l1.contains(Character.toString(s.charAt(i))))

                        count++;

            }

            output1 = count;

      }

      public static void main(String[] args) {

            fn("aeiouaa");

            System.out.println(output1);

      }

}