csTechie

    public static boolean isVowel(char inp) {
        char c = Character.toUpperCase(inp);

        if ((c == 'A') || (c == 'E') || (c == 'I') || (c == 'O') || (c == 'U')) {
            return true;
        }

        return false;
    }

    public static void reverseVowels(char[] a) {
        int start = 0;
        int end = a.length - 1;

        while (start < end) {
            while ((start < a.length) && !isVowel(a[start])) {
                start++;
            }

            while ((end > 0) && !isVowel(a[end])) {
                end--;
            }

            if ((start > = end) || (start == a.length) || (end == -1)) {
                return;
            }

            //swap start and end;
            char t = a[start];
            a[start] = a[end];
            a[end] = t;
            start++;
            end--;
        }
    }