.net的des加密方法,怎么用java实现. 多谢 分不够再加~

/// <summary>        /// 使用指定的加密算法、用随机密钥加密字符串        /// </summary>        /// <param name="Source">要加密的字符串</param>        /// <returns>加密结果</returns>        public string Encrypting(string Source,string Key)        {            #region temp            string strTemp = Key;            if(strTemp.Length * 8 > objCryptoService.LegalKeySizes[0].MaxSize)            {                // 如果密钥长度太长得话，截                strTemp = strTemp.Substring(0,objCryptoService.LegalKeySizes[0].MaxSize / 8);            }            if(strTemp.Length * 8 < objCryptoService.LegalKeySizes[0].MinSize)            {                // 如果密钥长度太短得的话，在右边补空格                strTemp = strTemp.PadRight(objCryptoService.LegalKeySizes[0].MinSize / 8);            }            if(objCryptoService.LegalKeySizes[0].SkipSize != 0 && (strTemp.Length * 8) % objCryptoService.LegalKeySizes[0].SkipSize != 0)            {                // 如果密钥长度不是密钥长度间隔单位的倍数，则补空格。                strTemp = strTemp.PadRight(objCryptoService.LegalKeySizes[0].MaxSize / 8);            }            byte[] _Key = System.Text.Encoding.Default.GetBytes(strTemp);            objCryptoService.Key = _Key;            objCryptoService.IV = _Key;            #endregion            // 创建内存中的数据流            System.IO.MemoryStream objMemoryStream = new System.IO.MemoryStream();            // 创建加密器            ICryptoTransform objEncryptor = objCryptoService.CreateEncryptor();            // 创建加密转换文件流的加密流            CryptoStream objCryptoStream = new CryptoStream(objMemoryStream, objEncryptor, CryptoStreamMode.Write);            StreamWriter writer = new StreamWriter(objCryptoStream);            writer.Write(Source);            writer.Flush();            objCryptoStream.FlushFinalBlock();            // 获取输出            byte[] bytOut = new byte[objMemoryStream.Length];            objMemoryStream.Position = 0;            objMemoryStream.Read(bytOut,0,bytOut.Length);            string strDest = System.Convert.ToBase64String(bytOut);            objCryptoService.Clear();            objMemoryStream.Close();            writer.Close();            return strDest;        }