public static ArrayList<Character> getLongestCommonSubstring(char[] array1, char[] array2) {
    ArrayList<Character> charArray = new ArrayList<>();
    ArrayList<Character> tempArray = new ArrayList<>();
    boolean canAddNextCharacter = false;
    int index = 0;
    for (int i = 0; i < array1.length; i ++) {
        for(int j = index; j < array2.length; j++) {
            if(array1[i] != array2[j]) {
                continue;
            }

            if(array1[i] == array2[j]) {
                charArray.add(array1[i]);
                canAddNextCharacter = ((j + 1) < array2.length - 1) && ((i+1) < array1.length -1) && (array1[i+1] == array2[j+1]);
                break;
            }
            canAddNextCharacter = false;
        }

        if(charArray.size() > tempArray.size()) {
            tempArray = charArray;
        }

        if(!canAddNextCharacter) {
            charArray = new ArrayList<>();
            index = 0;
        }
    }
    return tempArray;
}