Java回文总是返回true

public class Palindrome {
    public static boolean isPalindrome(String str) {
        String reversed = new StringBuilder(str).reverse().toString();
        return str.equals(reversed);
    }

    public static void main(String[] args) {
        String str = "level";
        boolean isPal = isPalindrome(str);
        System.out.println(isPal);  // 输出 true
    }
}