public class DESHelper
    {

        /// <summary>
        /// DES加密算法
        /// </summary>
        /// <param name="encryptString">要加密的字符串</param>
        /// <param name="sKey">加密码Key</param>
        /// <returns>正确返回加密后的结果，错误返回源字符串</returns>
        public static string ToDESEncrypt(string encryptString, string sKey)
        {
            try
            {

                byte[] keyBytes = Encoding.UTF8.GetBytes(sKey);
                byte[] keyIV = keyBytes;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);

                DESCryptoServiceProvider desProvider = new DESCryptoServiceProvider();

                // java 默认的是ECB模式，PKCS5padding；c#默认的CBC模式，PKCS7padding 所以这里我们默认使用ECB方式
                desProvider.Mode = CipherMode.ECB;
                MemoryStream memStream = new MemoryStream();
                CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateEncryptor(keyBytes, keyIV), CryptoStreamMode.Write);

                crypStream.Write(inputByteArray, 0, inputByteArray.Length);
                crypStream.FlushFinalBlock();
                return Convert.ToBase64String(memStream.ToArray());

            }
            catch
            {
                return encryptString;
            }
        }


        /// <summary>
        /// DES解密算法
        /// </summary>
        /// <param name="decryptString">要解密的字符串</param>
        /// <param name="sKey">加密Key</param>
        /// <returns>正确返回加密后的结果，错误返回源字符串</returns>
        public static string ToDESDecrypt(string decryptString, string sKey)
        {
            byte[] keyBytes = Encoding.UTF8.GetBytes(sKey);
            byte[] keyIV = keyBytes;
            byte[] inputByteArray = Convert.FromBase64String(decryptString);

            DESCryptoServiceProvider desProvider = new DESCryptoServiceProvider();

            // java 默认的是ECB模式，PKCS5padding；c#默认的CBC模式，PKCS7padding 所以这里我们默认使用ECB方式
            desProvider.Mode = CipherMode.ECB;
            MemoryStream memStream = new MemoryStream();
            CryptoStream crypStream = new CryptoStream(memStream, desProvider.CreateDecryptor(keyBytes, keyIV), CryptoStreamMode.Write);

            crypStream.Write(inputByteArray, 0, inputByteArray.Length);
            crypStream.FlushFinalBlock();
            return Encoding.Default.GetString(memStream.ToArray());

        }
    }

public class DESHelper {

	private byte[] desKey;

	public DES(String desKey) {
		this.desKey = desKey.getBytes();
	}

	public byte[] desEncrypt(byte[] plainText) throws Exception {
		SecureRandom sr = new SecureRandom();
		byte rawKeyData[] = desKey;
		DESKeySpec dks = new DESKeySpec(rawKeyData);
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey key = keyFactory.generateSecret(dks);
		Cipher cipher = Cipher.getInstance("DES");
		cipher.init(Cipher.ENCRYPT_MODE, key, sr);
		byte data[] = plainText;
		byte encryptedData[] = cipher.doFinal(data);
		return encryptedData;
	}

	public byte[] desDecrypt(byte[] encryptText) throws Exception {
		SecureRandom sr = new SecureRandom();
		byte rawKeyData[] = desKey;
		DESKeySpec dks = new DESKeySpec(rawKeyData);
		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey key = keyFactory.generateSecret(dks);
		Cipher cipher = Cipher.getInstance("DES");
		cipher.init(Cipher.DECRYPT_MODE, key, sr);
		byte encryptedData[] = encryptText;
		byte decryptedData[] = cipher.doFinal(encryptedData);
		return decryptedData;
	}

	public String encrypt(String input) throws Exception {
		return base64Encode(desEncrypt(input.getBytes()));
	}

	public String decrypt(String input) throws Exception {
		byte[] result = base64Decode(input);
		return new String(desDecrypt(result));
	}

	public static String base64Encode(byte[] s) {
		if (s == null)
			return null;
		BASE64Encoder b = new sun.misc.BASE64Encoder();
		return b.encode(s);
	}

	public static byte[] base64Decode(String s) throws IOException {
		if (s == null)
			return null;
		BASE64Decoder decoder = new BASE64Decoder();
		byte[] b = decoder.decodeBuffer(s);
		return b;
	}
	
}