Java使用AES 256和128对称密钥加密

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class AESEncryption {
    private static final String AES_ALGORITHM = "AES";

    public static String encrypt(String plaintext, String key) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), AES_ALGORITHM);
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte[] encryptedBytes = cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));
        return Base64.getEncoder().encodeToString(encryptedBytes);
    }

    public static String decrypt(String ciphertext, String key) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key.getBytes(StandardCharsets.UTF_8), AES_ALGORITHM);
        Cipher cipher = Cipher.getInstance(AES_ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(ciphertext));
        return new String(decryptedBytes, StandardCharsets.UTF_8);
    }

    public static void main(String[] args) throws Exception {
        String plaintext = "Hello, World!";
        String key = "0123456789abcdef"; // 128-bit key

        String encryptedText = encrypt(plaintext, key);
        System.out.println("Encrypted Text: " + encryptedText);

        String decryptedText = decrypt(encryptedText, key);
        System.out.println("Decrypted Text: " + decryptedText);
    }
}