Why this function not return palindrome count?

Question

Why does this code does not work?
str get "abc redder noon" and function should return count Word == palindrome

in this case, I should return 2!;

public static int countPolindroms(String str) {
    int countWords = 0, start = 0, last, i;
    boolean flag = true;

    str=str.toUpperCase();
    for (i = 0; i < str.length(); i++) {
        if (str.charAt(i) == ' ' || i == str.length() - 1) {
            if (i != str.length() - 1)
                last = i - 1;
            else
                last = i;

            for ( ;start < last && flag ; start++, last--) {
                if(str.charAt(start) != str.charAt(last))
                    flag = false;
            }
            if (flag)
                countWords++;
            if (str.charAt(i) == ' ')
                start = i + 1;
        }
    }
    return countWords;
}