Cookie中存放数据l加密解密的算法

public class CookieUtil {

/**
*
* @param response HttpServletResponse类型的响应
* @param cookie 要设置httpOnly的cookie对象
*/
public static void addHttpOnlyCookie(HttpServletResponse response,
Cookie cookie) {
// 判断对象是否存在null的情况
if (checkObjIsNull(response) || checkObjIsNull(cookie)) {
return;
}

//依次取得cookie中的名称、值、最大生存时间、路径、域和是否为安全协议信息
String cookieName = cookie.getName();
String cookieValue = cookie.getValue();
int maxAge = cookie.getMaxAge();
String path = cookie.getPath();
String domain = cookie.getDomain();
boolean isSecure = cookie.getSecure();

StringBuffer strBufferCookie = new StringBuffer();
strBufferCookie.append(cookieName + "=" + cookieValue + ";");

if (maxAge >= 0) {
strBufferCookie.append("Max-Age=" + maxAge + ";");
} else {
strBufferCookie.append("Max-Age=25;");
}

if (!checkObjIsNull(domain)) {
strBufferCookie.append("domain=" + domain + ";");
}

if (!checkObjIsNull(path)) {
strBufferCookie.append("path=" + path + ";");
}

if (isSecure) {
strBufferCookie.append("HttpOnly;Secure;");
} else {
strBufferCookie.append("HttpOnly;");
}

response.addHeader("Set-Cookie", strBufferCookie.toString());
}

private static boolean checkObjIsNull(Object obj) {
if (obj == null) {
return true;
}
return false;
}

/**
* cookie中的值加密
*/
public static String encodeCookie(String value){
String encode = "";
byte bytes[];
try {
bytes = value.getBytes("utf-8");
encode = encode_base64(bytes,bytes.length);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return encode;
}
/**
* cookie中值解密
*/
public static String decodeCookie(String value){
byte bytes[];
String decode = "";
try {
bytes = decode_base64(value,10);
decode = new String(bytes,"UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return decode;
}

static private final char base64_code[] = {
'.', '/', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9'
};

// Table for Base64 decoding
static private final byte index_64[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, 0, 1, 54, 55,
56, 57, 58, 59, 60, 61, 62, 63, -1, -1,
-1, -1, -1, -1, -1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
-1, -1, -1, -1, -1, -1, 28, 29, 30,
31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
51, 52, 53, -1, -1, -1, -1, -1
};
private static String encode_base64(byte d[], int len)	throws IllegalArgumentException {
int off = 0;
StringBuffer rs = new StringBuffer();
int c1, c2;

if (len <= 0 || len > d.length)
throw new IllegalArgumentException ("Invalid len");

while (off < len) {
c1 = d[off++] & 0xff;
rs.append(base64_code[(c1 >> 2) & 0x3f]);
c1 = (c1 & 0x03) << 4;
if (off >= len) {
rs.append(base64_code[c1 & 0x3f]);
break;
}
c2 = d[off++] & 0xff;
c1 |= (c2 >> 4) & 0x0f;
rs.append(base64_code[c1 & 0x3f]);
c1 = (c2 & 0x0f) << 2;
if (off >= len) {
rs.append(base64_code[c1 & 0x3f]);
break;
}
c2 = d[off++] & 0xff;
c1 |= (c2 >> 6) & 0x03;
rs.append(base64_code[c1 & 0x3f]);
rs.append(base64_code[c2 & 0x3f]);
}
return rs.toString();
}
private static byte char64(char x) {
if ((int)x < 0 || (int)x > index_64.length)
return -1;
return index_64[(int)x];
}
private static byte[] decode_base64(String s, int maxolen) throws IllegalArgumentException {
StringBuffer rs = new StringBuffer();
int off = 0, slen = s.length(), olen = 0;
byte ret[];
byte c1, c2, c3, c4, o;

if (maxolen <= 0)
throw new IllegalArgumentException ("Invalid maxolen");
while (off < slen - 1 && olen < maxolen) {
c1 = char64(s.charAt(off++));
c2 = char64(s.charAt(off++));
if (c1 == -1 || c2 == -1)
break;
o = (byte)(c1 << 2);
o |= (c2 & 0x30) >> 4;
rs.append((char)o);
if (++olen >= maxolen || off >= slen)
break;
c3 = char64(s.charAt(off++));
if (c3 == -1)
break;
o = (byte)((c2 & 0x0f) << 4);
o |= (c3 & 0x3c) >> 2;
rs.append((char)o);
if (++olen >= maxolen || off >= slen)
break;
c4 = char64(s.charAt(off++));
o = (byte)((c3 & 0x03) << 6);
o |= c4;
rs.append((char)o);
++olen;
}

ret = new byte[olen];
for (off = 0; off < olen; off++)
ret[off] = (byte)rs.charAt(off);
return ret;
}

public static void main(String[] args) {
encodeCookie("admin");
//		[97, 100, 109, 105, 110]
//		[97, 100, 109, 105, 110]
decodeCookie("WUPrYU2");
}
}