java易懂易用的MD5加密(可直接运行) (1)

/**
* 进行MD5加密
* @param String 原始的SPKEY
* @return byte[] 指定加密方式为md5后的byte[]
*/
private byte[] md5(String strSrc)
{
byte[] returnByte = null;
try
{
MessageDigest md5 = MessageDigest.getInstance("MD5");
returnByte = md5.digest(strSrc.getBytes("GBK"));
}
catch(Exception e)
{
e.printStackTrace();
}
return returnByte;
}

/**
* 得到3-DES的密钥匙
* 根据根据需要，如密钥匙为24个字节，md5加密出来的是16个字节，因此后面补8个字节的0
* @param String 原始的SPKEY
* @return byte[] 指定加密方式为md5后的byte[]
*/
private byte[] getEnKey(String spKey)
{
byte[] desKey=null;
try
{
byte[] desKey1 = md5(spKey);
desKey = new byte[24];
int i = 0;
while (i < desKey1.length && i < 24) {
desKey[i] = desKey1[i];
i++;
}
if (i < 24) {
desKey[i] = 0;
i++;
}
}
catch(Exception e){
e.printStackTrace();
}
return desKey;
}

/**
* 3-DES加密
* @param byte[] src 要进行3-DES加密的byte[]
* @param byte[] enKey 3-DES加密密钥
* @return byte[] 3-DES加密后的byte[]
*/
public byte[] Encrypt(byte[] src,byte[] enKey)
{
byte[] encryptedData = null;
try
{
DESedeKeySpec dks = new DESedeKeySpec(enKey);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey key = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DESede");
cipher.init(Cipher.ENCRYPT_MODE, key);
encryptedData = cipher.doFinal(src);
}
catch(Exception e)
{
e.printStackTrace();
}
return encryptedData;
}

/**
* 对字符串进行Base64编码
* @param byte[] src 要进行编码的字符
*
* @return String 进行编码后的字符串
*/
public String getBase64Encode(byte[] src)
{
String requestValue="";
try{
BASE64Encoder base64en = new BASE64Encoder();
requestValue=base64en.encode(src);
//System.out.println(requestValue);
}
catch(Exception e){
e.printStackTrace();
}

return requestValue;
}

/**
* 去掉字符串的换行符号
* base64编码3-DES的数据时，得到的字符串有换行符号，根据需要可以去掉
*/
private String filter(String str)
{
String output = null;
StringBuffer sb = new StringBuffer();
for(int i = 0; i < str.length(); i++)
{
int asc = str.charAt(i);
if(asc != 10 && asc != 13)
sb.append(str.subSequence(i, i + 1));
}
output = new String(sb);
return output;
}

/**
* 对字符串进行URLDecoder.encode(strEncoding)编码
* @param String src 要进行编码的字符串
*
* @return String 进行编码后的字符串
*/
public String getURLEncode(String src)
{
String requestValue="";
try{

requestValue = URLEncoder.encode(src);
}
catch(Exception e){
e.printStackTrace();
}

return requestValue;
}

/**
* 对字符串进行URLDecoder.decode(strEncoding)解码
* @param String src 要进行解码的字符串
*
* @return String 进行解码后的字符串
*/
public String getURLDecoderdecode(String src)
{
String requestValue="";
try{

requestValue = URLDecoder.decode(src);
}
catch(Exception e){
e.printStackTrace();
}

return requestValue;
}

/**
*
*进行3-DES解密（密钥匙等同于加密的密钥匙）。
* @param byte[] src 要进行3-DES解密byte[]
* @param String spkey分配的SPKEY
* @return String 3-DES解密后的String
*/
public String deCrypt(byte[] debase64,String spKey)
{
String strDe = null;
Cipher cipher = null;
try
{
cipher=Cipher.getInstance("DESede");
byte[] key = getEnKey(spKey);
DESedeKeySpec dks = new DESedeKeySpec(key);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey sKey = keyFactory.generateSecret(dks);
cipher.init(Cipher.DECRYPT_MODE, sKey);
byte ciphertext[] = cipher.doFinal(debase64);
strDe = new String(ciphertext,"UTF-16LE");
}
catch(Exception ex)
{
strDe = "";
ex.printStackTrace();
}
return strDe;