用Java写一个加密和解密的代码

好的，我可以帮您编写一个Java的加密和解密代码。加密与解密可以用对称加密方式实现，比如AES加密算法。您需要输入要加密的明文消息和密钥，然后程序会输出加密后的密文。同样，您也可以输入密文和密钥来解密消息。以下是简单的示例代码：

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class Encryption {

    private static final String ALGORITHM = "AES";
    private static final String TRANSFORMATION = "AES/ECB/PKCS5Padding";

    public static String encrypt(String plainText, String key) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] cipherText = cipher.doFinal(plainText.getBytes());
        return Base64.getEncoder().encodeToString(cipherText);
    }

    public static String decrypt(String cipherText, String key) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(), ALGORITHM);
        Cipher cipher = Cipher.getInstance(TRANSFORMATION);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] plainText = cipher.doFinal(Base64.getDecoder().decode(cipherText));
        return new String(plainText);
    }

    public static void main(String[] args) throws Exception {
        String plainText = "Hello, world!";
        String key = "my-secure-key";
        String encryptedText = encrypt(plainText, key);
        System.out.println("Encrypted text: " + encryptedText);
        String decryptedText = decrypt(encryptedText, key);
        System.out.println("Decrypted text: " + decryptedText);
    }
}

需要注意的是，暴力破解加密密文是一种不道德而且可能不合法的行为，请谨慎使用加密技术，以保护您和他人的隐私。