(转)Java DES 与Base64

原文地址http://blog.csdn.net/tomatozq/article/details/20773559

1，DES

    /**
             * 解密
             * @param message
             * @param key
             * @return
             * @throws Exception
             */
            public static String decrypt(String message,String encoding) throws Exception {  

                byte[] bytesrc = convertHexString(message);
                Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
                DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(encoding));
                SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
                SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
                IvParameterSpec iv = new IvParameterSpec(key.getBytes(encoding));  

                cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);  

                byte[] retByte = cipher.doFinal(bytesrc);
                return new String(retByte,encoding);
            }  

            /**
             * 加密
             * @param message
             * @param key
             * @return
             * @throws Exception
             */
            public static String encrypt(String message,String encoding) throws Exception {
                Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");  

                DESKeySpec desKeySpec = new DESKeySpec(key.getBytes(encoding));  

                SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
                SecretKey secretKey = keyFactory.generateSecret(desKeySpec);
                IvParameterSpec iv = new IvParameterSpec(key.getBytes(encoding));
                cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);  

                byte[] buf = cipher.doFinal(message.getBytes(encoding));  

                String a = toHexString(buf).toUpperCase();  

                return a;
            }  

            /**
             * 字符串转换为16进制数组
             * @param ss
             * @return
             */
            public static byte[] convertHexString(String ss) {
                byte digest[] = new byte[ss.length() / 2];
                for (int i = 0; i < digest.length; i++) {
                    String byteString = ss.substring(2 * i, 2 * i + 2);
                    int byteValue = Integer.parseInt(byteString, 16);
                    digest[i] = (byte) byteValue;
                }  

                return digest;
            }  

            /**
             * 16进制数组转换为字符串
             * @param b
             * @return
             */
            public static String toHexString(byte b[]) {
                StringBuffer hexString = new StringBuffer();
                for (int i = 0; i < b.length; i++) {
                    String plainText = Integer.toHexString(0xff & b[i]);
                    if (plainText.length() < 2)
                        plainText = "0" + plainText;
                    hexString.append(plainText);
                }  

                return hexString.toString();
            }

2，Base64

    byte[] enc = Base64.encode(encText.getBytes(encoding), Base64.DEFAULT);
    byte[] bytesrc = Base64.decode(encText.getBytes(encoding), Base64.DEFAULT);