/**
* Scans an external ID.
*
* @param f full flag
* @param r root flag
* @return id
* @throws IOException I/O exception
*/
private byte[] externalID(final boolean f, final boolean r) throws IOException {
byte[] cont = null;
final boolean pub = consume(PUBLIC);
if (pub || consume(SYSTEM)) {
checkS();
if (pub) {
pubidLit();
if (f) checkS();
}
final int qu = consume(); // [11]
if (qu == '\'' || qu == '"') {
int ch;
final TokenBuilder tok = new TokenBuilder();
while ((ch = nextChar()) != qu) tok.add(ch);
if (!f) return null;
final String name = string(tok.finish());
if (!dtd && r) return cont;
final XMLInput tin = input;
try {
final IO file = input.io().merge(name);
cont = file.read();
} catch (final IOException ex) {
Util.debug(ex);
// skip unknown DTDs/entities
cont = new byte[] {'?'};
}
input = new XMLInput(new IOContent(cont, name));
if (consume(XDECL)) {
check(XML);
s();
if (version()) checkS();
s();
if (encoding() == null) error(TEXTENC);
ch = nextChar();
if (s(ch)) ch = nextChar();
if (ch != '?') error(WRONGCHAR, '?', ch);
ch = nextChar();
if (ch != '>') error(WRONGCHAR, '>', ch);
cont = Arrays.copyOfRange(cont, input.pos(), cont.length);
}
s();
if (r) {
extSubsetDecl();
if (!consume((char) 0)) error(INVEND);
}
input = tin;
} else {
if (f) error(SCANQUOTE, (char) qu);
prev(1);
}
}
return cont;
}
@Override
public double prog() {
final double l = input.length();
return l <= 0 ? 0 : input.pos() / l;
}