麻烦帮我将下面这段变形的BASE64(非原型) JAVA版转为ASP版
public static String encode(byte data[])
{
return encode(data, 0, data.length);
}
public static String encode(byte data[], int off, int len)
{
if(len <= 0)
return " ";
char out[] = new char[(len / 3) * 4 + 4];
int rindex = off;
int windex = 0;
int rest;
for(rest = len - off; rest > = 3; rest -= 3)
{
int i = ((data[rindex] & 0xff) < < 16) + ((data[rindex + 1] & 0xff) < < 8) + (data[rindex + 2] & 0xff);
out[windex++] = S_BASE64CHAR[i > > 18];
out[windex++] = S_BASE64CHAR[i > > 12 & 0x3f];
out[windex++] = S_BASE64CHAR[i > > 6 & 0x3f];
out[windex++] = S_BASE64CHAR[i & 0x3f];
rindex += 3;
}
if(rest == 1)
{
int i = data[rindex] & 0xff;
out[windex++] = S_BASE64CHAR[i > > 2];
out[windex++] = S_BASE64CHAR[i < < 4 & 0x3f];
out[windex++] = '= ';
out[windex++] = '= ';
} else
if(rest == 2)
{
int i = ((data[rindex] & 0xff) < < 8) + (data[rindex + 1] & 0xff);
out[windex++] = S_BASE64CHAR[i > > 10];
out[windex++] = S_BASE64CHAR[i > > 4 & 0x3f];
out[windex++] = S_BASE64CHAR[i < < 2 & 0x3f];
out[windex++] = '= ';
}
return new String(out, 0, windex);
}
private static final char S_BASE64CHAR[] = {
'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 ', '+ ', '/ '
};
private static final char S_BASE64PAD = 61;
private static final byte S_DECODETABLE[];
[解决办法]
另提供一段原型的BASE64原型ASP版作参考
OPTION EXPLICIT
const BASE_64_MAP_INIT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ "
dim nl
' zero based arrays
dim Base64EncMap(63)
dim Base64DecMap(127)
' must be called before using anything else
PUBLIC SUB initCodecs()
' init vars
nl = " <P> " & chr(13) & chr(10)
' setup base 64
dim max, idx
max = len(BASE_64_MAP_INIT)
for idx = 0 to max - 1
' one based string
Base64EncMap(idx) = mid(BASE_64_MAP_INIT, idx + 1, 1)
next
for idx = 0 to max - 1
Base64DecMap(ASC(Base64EncMap(idx))) = idx
next
END SUB
' encode base 64 encoded string
PUBLIC FUNCTION base64Encode(plain)
if len(plain) = 0 then
base64Encode = " "
exit function
end if
dim ret, ndx, by3, first, second, third
by3 = (len(plain) \ 3) * 3
ndx = 1
do while ndx <= by3
first = asc(mid(plain, ndx+0, 1))
second = asc(mid(plain, ndx+1, 1))
third = asc(mid(plain, ndx+2, 1))
ret = ret & Base64EncMap( (first \ 4) AND 63 )
ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second \ 16) AND 15 ) )
ret = ret & Base64EncMap( ((second * 4) AND 60) + ((third \ 64) AND 3 ) )
ret = ret & Base64EncMap( third AND 63)
ndx = ndx + 3
loop
' check for stragglers
if by3 < len(plain) then
first = asc(mid(plain, ndx+0, 1))
ret = ret & Base64EncMap( (first \ 4) AND 63 )
if (len(plain) MOD 3 ) = 2 then
second = asc(mid(plain, ndx+1, 1))
ret = ret & Base64EncMap( ((first * 16) AND 48) + ((second \ 16) AND 15 ) )
ret = ret & Base64EncMap( ((second * 4) AND 60) )
else
ret = ret & Base64EncMap( (first * 16) AND 48)
ret = ret & "= "
end if
ret = ret & "= "
end if
base64Encode = ret
END FUNCTION
