/**
* Replace occurrences of "%ab" with the character represented by the hex value. Strings of
* escaped characters are treated as UTF-8 byte sequences and decoded appropriately.
*/
private static String decode(String s) {
int length = s.length();
StringBuilder str = new StringBuilder(length);
Matcher matcher = PATTERN.matcher(s);
int offset = 0;
byte[] bb = null;
while (matcher.find(offset)) {
int count = matcher.groupCount();
for (int i = 0; i < count; i++) {
String match = matcher.group(0);
int num = match.length() / 3;
if (bb == null || bb.length < num) {
bb = new byte[num];
}
for (int j = 0; j < num; j++) {
int head = j * 3 + 1;
int tail = head + 2;
bb[j] = (byte) Integer.parseInt(match.substring(head, tail), 16);
}
try {
String text = new String(bb, "UTF-8");
str.append(s.substring(offset, matcher.start()));
str.append(text);
} catch (UnsupportedEncodingException e) {
// NOTE: This should *never* be thrown because all
// JVMs are required to support UTF-8. I mean,
// the strings in the .class file are all in
// a modified UTF-8, for pete's sake! :)
}
}
offset = matcher.end();
}
if (offset < length) {
str.append(s.substring(offset));
}
return str.toString();
}
