/**     * DES加密     *     * @param data 加密数据     * @param key  密钥     * @return 返回加密后的数据     */    public static byte[] desEncrypt(byte[] data, String key, String charset) {        try {            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");            byte[] k = charset == null || charset.trim().isEmpty() ? key.getBytes() : key.getBytes(charset);            SecretKey secretKey = SecretKeyFactory.getInstance("DES").generateSecret(new DESKeySpec(k));            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(k));            return cipher.doFinal(data);        } catch (Exception e) {            return null;        }    }    /**     * DES解密     *     * @param data 解密数据     * @param key  密钥     * @return 返回解密后的数据     */    public static String desDecrypt(byte[] data, String key, String charset) {        try {            Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");            byte[] k = charset == null || charset.trim().isEmpty() ? key.getBytes() : key.getBytes(charset);            cipher.init(Cipher.DECRYPT_MODE, SecretKeyFactory.getInstance("DES").generateSecret(new DESKeySpec(k)), new IvParameterSpec(k));            if (charset == null || charset.trim().isEmpty()) {                return new String(cipher.doFinal(data));            }            return new String(cipher.doFinal(data), charset);        } catch (Exception e) {            return null;        }    }