我想使用AES加密技術(shù)對(duì)郵件進(jìn)行加密。當(dāng)我使用此代碼時(shí)，我遇到了一些錯(cuò)誤java.security.InvalidKeyException: Illegal key size or default parameters我的加密代碼：public class Encryption {    public static class MessageEncrypt {        public static class AES {            private final static String ALGO = "AES";            private String secretKey;            private String data;            public String encrypt(String secretKey, String data) throws Exception {                SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");                KeySpec spec = new PBEKeySpec(secretKey.toCharArray(), secretKey.getBytes(), 128, 256);                SecretKey tmp = factory.generateSecret(spec);                SecretKey key = new SecretKeySpec(tmp.getEncoded(), ALGO);                Cipher cipher = Cipher.getInstance(ALGO);                cipher.init(Cipher.ENCRYPT_MODE, key);                return toHex(cipher.doFinal(data.getBytes()));            }            public String decrypt(String secretKey, String data) throws Exception {                SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");                KeySpec spec = new PBEKeySpec(secretKey.toCharArray(), secretKey.getBytes(), 128, 256);                SecretKey tmp = factory.generateSecret(spec);                SecretKey key = new SecretKeySpec(tmp.getEncoded(), ALGO);                Cipher cipher = Cipher.getInstance(ALGO);                cipher.init(Cipher.DECRYPT_MODE, key);                return new String(cipher.doFinal(toByte(data)));            }            private static byte[] toByte(String hexString) {                int len = hexString.length() / 2;                byte[] result = new byte[len];                for (int i = 0; i < len; i++)                    result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 16).byteValue();                return result;            }