finding common letters

Workouts999.java

import java.util.ArrayList;
import java.util.List;

public class Workouts999 {

    /**
     * common letters
     */
    public static void main(String[] args) {
        String word1 = "always";
        String word2 = "following";
        System.out.println(findCommonLetters(word1.toCharArray(), word2.toCharArray()));
    }

    private static List<Character> findCommonLetters(char[] array1, char[] array2) {

        List<Character> characterList = new ArrayList<Character>();

        for (char element1 : array1) {
            for (char element2 : array2) {
                if (element1 == element2 && !characterList.contains(element1)) {
                    characterList.add(element2);
                }
            }
        }

        return characterList;
    }
}

Output:
[l, w]