Example: PalindromeCheckStringBuilder in Java

// PalindromeCheckStringBuilder
import java.util.Scanner;

public class Main {

    // Helper method to preprocess the string
    private static String preprocessString(String s) {
        StringBuilder cleanedString = new StringBuilder();
        for (char c : s.toCharArray()) {
            if (Character.isLetterOrDigit(c)) {
                cleanedString.append(Character.toLowerCase(c));
            }
        }
        return cleanedString.toString();
    }

    // Method to check for palindrome using StringBuilder.reverse()
    public static boolean isPalindromeStringBuilder(String s) {
        String cleaned = preprocessString(s);
        String reversedCleaned = new StringBuilder(cleaned).reverse().toString();
        return cleaned.equals(reversedCleaned);
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Step 1: Get input string from the user
        System.out.print("Enter a string to check for palindrome: ");
        String inputString = scanner.nextLine();

        // Step 2: Check if it's a palindrome using the StringBuilder method
        if (isPalindromeStringBuilder(inputString)) {
            System.out.println("'" + inputString + "' is a palindrome (StringBuilder Method).");
        } else {
            System.out.println("'" + inputString + "' is NOT a palindrome (StringBuilder Method).");
        }

        scanner.close();
    }
}