public static StringBuffer convertToUnicode(UCharacterIterator iter, int options)
throws StringPrepParseException {
// the source contains all ascii codepoints
boolean srcIsASCII = true;
int ch;
int saveIndex = iter.getIndex();
// step 1: find out if all the codepoints in src are ASCII
while ((ch = iter.next()) != UCharacterIterator.DONE) {
if (ch > 0x7F) {
srcIsASCII = false;
break;
}
}
// The RFC states that
// <quote>
// ToUnicode never fails. If any step fails, then the original input
// is returned immediately in that step.
// </quote>
do {
StringBuffer processOut;
if (srcIsASCII == false) {
// step 2: process the string
iter.setIndex(saveIndex);
try {
processOut = transform.prepare(iter, options);
} catch (StringPrepParseException e) {
break;
}
} else {
// just point to source
processOut = new StringBuffer(iter.getText());
}
// step 3: verify ACE Prefix
if (startsWithPrefix(processOut)) {
// step 4: Remove the ACE Prefix
String temp = processOut.substring(ACE_PREFIX_LENGTH, processOut.length());
// step 5: Decode using punycode
StringBuffer decodeOut = null;
try {
decodeOut = PunycodeReference.decode(new StringBuffer(temp), null);
} catch (StringPrepParseException e) {
break;
}
// step 6:Apply toASCII
StringBuffer toASCIIOut = convertToASCII(decodeOut, options);
// step 7: verify
if (compareCaseInsensitiveASCII(processOut, toASCIIOut) != 0) {
break;
}
// step 8: return output of step 5
return decodeOut;
}
} while (false);
return new StringBuffer(iter.getText());
}
public static StringBuffer convertToASCII(UCharacterIterator srcIter, int options)
throws StringPrepParseException {
char[] caseFlags = null;
// the source contains all ascii codepoints
boolean srcIsASCII = true;
// assume the source contains all LDH codepoints
boolean srcIsLDH = true;
// get the options
boolean useSTD3ASCIIRules = ((options & USE_STD3_RULES) != 0);
int ch;
// step 1
while ((ch = srcIter.next()) != UCharacterIterator.DONE) {
if (ch > 0x7f) {
srcIsASCII = false;
}
}
int failPos = -1;
srcIter.setToStart();
StringBuffer processOut = null;
// step 2 is performed only if the source contains non ASCII
if (!srcIsASCII) {
// step 2
processOut = transform.prepare(srcIter, options);
} else {
processOut = new StringBuffer(srcIter.getText());
}
int poLen = processOut.length();
if (poLen == 0) {
throw new StringPrepParseException(
"Found zero length lable after NamePrep.", StringPrepParseException.ZERO_LENGTH_LABEL);
}
StringBuffer dest = new StringBuffer();
// reset the variable to verify if output of prepare is ASCII or not
srcIsASCII = true;
// step 3 & 4
for (int j = 0; j < poLen; j++) {
ch = processOut.charAt(j);
if (ch > 0x7F) {
srcIsASCII = false;
} else if (isLDHChar(ch) == false) {
// here we do not assemble surrogates
// since we know that LDH code points
// are in the ASCII range only
srcIsLDH = false;
failPos = j;
}
}
if (useSTD3ASCIIRules == true) {
// verify 3a and 3b
if (srcIsLDH == false /* source contains some non-LDH characters */
|| processOut.charAt(0) == HYPHEN
|| processOut.charAt(processOut.length() - 1) == HYPHEN) {
/* populate the parseError struct */
if (srcIsLDH == false) {
throw new StringPrepParseException(
"The input does not conform to the STD 3 ASCII rules",
StringPrepParseException.STD3_ASCII_RULES_ERROR,
processOut.toString(),
(failPos > 0) ? (failPos - 1) : failPos);
} else if (processOut.charAt(0) == HYPHEN) {
throw new StringPrepParseException(
"The input does not conform to the STD 3 ASCII rules",
StringPrepParseException.STD3_ASCII_RULES_ERROR,
processOut.toString(),
0);
} else {
throw new StringPrepParseException(
"The input does not conform to the STD 3 ASCII rules",
StringPrepParseException.STD3_ASCII_RULES_ERROR,
processOut.toString(),
(poLen > 0) ? poLen - 1 : poLen);
}
}
}
if (srcIsASCII) {
dest = processOut;
} else {
// step 5 : verify the sequence does not begin with ACE prefix
if (!startsWithPrefix(processOut)) {
// step 6: encode the sequence with punycode
StringBuffer punyout = PunycodeReference.encode(processOut, caseFlags);
// convert all codepoints to lower case ASCII
StringBuffer lowerOut = toASCIILower(punyout);
// Step 7: prepend the ACE prefix
dest.append(ACE_PREFIX, 0, ACE_PREFIX_LENGTH);
// Step 6: copy the contents in b2 into dest
dest.append(lowerOut);
} else {
throw new StringPrepParseException(
"The input does not start with the ACE Prefix.",
StringPrepParseException.ACE_PREFIX_ERROR,
processOut.toString(),
0);
}
}
if (dest.length() > MAX_LABEL_LENGTH) {
throw new StringPrepParseException(
"The labels in the input are too long. Length > 64.",
StringPrepParseException.LABEL_TOO_LONG_ERROR,
dest.toString(),
0);
}
return dest;
}
