Java AES -密钥的消息摘要

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.security.MessageDigest;
import java.util.Arrays;

public class JavaAESExample {
    private static final String ALGORITHM = "AES";
    private static final String KEY = "mySecretKey12345";

    public static void main(String[] args) throws Exception {
        String originalMessage = "Hello, World!";
        
        // 加密
        byte[] encryptedMessage = encrypt(originalMessage);
        System.out.println("Encrypted Message: " + Arrays.toString(encryptedMessage));
        
        // 解密
        String decryptedMessage = decrypt(encryptedMessage);
        System.out.println("Decrypted Message: " + decryptedMessage);
        
        // 消息摘要
        String messageDigest = getMessageDigest(originalMessage);
        System.out.println("Message Digest: " + messageDigest);
    }

    private static byte[] encrypt(String message) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(KEY.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return cipher.doFinal(message.getBytes());
    }

    private static String decrypt(byte[] encryptedMessage) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(KEY.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(encryptedMessage);
        return new String(decryptedBytes);
    }

    private static String getMessageDigest(String message) throws Exception {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        byte[] hash = digest.digest(message.getBytes());
        StringBuilder hexString = new StringBuilder();
        for (byte b : hash) {
            String hex = Integer.toHexString(0xff & b);
            if (hex.length() == 1) hexString.append('0');
            hexString.append(hex);
        }
        return hexString.toString();
    }
}