Java SHA不工作。哈希值不等于字符串。我的编码有问题吗？

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHAExample {
    public static void main(String[] args) {
        String input = "Hello World";
        
        try {
            MessageDigest sha = MessageDigest.getInstance("SHA-256");
            byte[] hash = sha.digest(input.getBytes());
            
            // 将字节数组转换为十六进制字符串
            StringBuilder hexString = new StringBuilder();
            for (byte b : hash) {
                String hex = Integer.toHexString(0xff & b);
                if (hex.length() == 1) {
                    hexString.append('0');
                }
                hexString.append(hex);
            }
            
            System.out.println("SHA-256 Hash: " + hexString.toString());
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
    }
}