public Set<String> findAllPalindromesUsingBruteForceApproach(String input) {
    Set<String> palindromes = new HashSet<>();
    for (int i = 0; i < input.length(); i++) {
        for (int j = i + 1; j <= input.length(); j++) {
            if (isPalindrome(input.substring(i, j))) {
                palindromes.add(input.substring(i, j));
            }
        }
    }
    return palindromes;
}

private boolean isPalindrome(String input) {
    StringBuilder plain = new StringBuilder(input);
    StringBuilder reverse = plain.reverse();
    return (reverse.toString()).equals(input);
}