Decodes an array quoted-printable characters into an array of original bytes.
Escaped characters are converted back to their original representation.
This function implements a subset of
quoted-printable encoding specification (rule #1 and rule #2)
as defined in RFC 1521.
if (bytes == null) {
return null;
}
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
for (int i = 0; i < bytes.length; i++) {
int b = bytes[i];
if (b == ESCAPE_CHAR) {
try {
if('\r" == (char)bytes[i + 1] &&
'\n" == (char)bytes[i + 2]) {
i += 2;
continue;
}
int u = Character.digit((char) bytes[++i], 16);
int l = Character.digit((char) bytes[++i], 16);
if (u == -1 || l == -1) {
return null;
}
buffer.write((char) ((u << 4) + l));
} catch (ArrayIndexOutOfBoundsException e) {
return null;
}
} else {
buffer.write(b);
}
}
return buffer.toByteArray();
