/**
* Visit all bytes of the given utf8 string calling the visitor when a character is decoded.
*
* <p>The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8,
* and ALLOW_PSEUDO_UTF8 flags.
*
* @param utf8 (pseudo-)utf8 byte array
* @param visitor called when characters are decoded
* @throws UTFDataFormatException if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8
*/
@Inline
private static void visitUTF8(ByteBuffer utf8, UTF8CharacterVisitor visitor)
throws UTFDataFormatException {
while (utf8.hasRemaining()) {
byte b = utf8.get();
if (STRICTLY_CHECK_FORMAT && !ALLOW_NORMAL_UTF8) {
if (b == 0) {
throwDataFormatException("0 byte encountered", utf8.position() - 1);
}
}
if (b >= 0) { // < 0x80 unsigned
// in the range '\001' to '\177'
visitor.visit_char((char) b);
continue;
}
try {
byte nb = utf8.get();
if (b < -32) { // < 0xe0 unsigned
// '\000' or in the range '\200' to '\u07FF'
char c = (char) (((b & 0x1f) << 6) | (nb & 0x3f));
visitor.visit_char(c);
if (STRICTLY_CHECK_FORMAT) {
if (((b & 0xe0) != 0xc0) || ((nb & 0xc0) != 0x80)) {
throwDataFormatException(
"invalid marker bits for double byte char", utf8.position() - 2);
}
if (c < '\200') {
if (!ALLOW_PSEUDO_UTF8 || (c != '\000')) {
throwDataFormatException(
"encountered double byte char that should have been single byte",
utf8.position() - 2);
}
} else if (c > '\u07FF') {
throwDataFormatException(
"encountered double byte char that should have been single byte",
utf8.position() - 2);
}
}
} else {
byte nnb = utf8.get();
// in the range '\u0800' to '\uFFFF'
char c = (char) (((b & 0x0f) << 12) | ((nb & 0x3f) << 6) | (nnb & 0x3f));
visitor.visit_char(c);
if (STRICTLY_CHECK_FORMAT) {
if (((b & 0xf0) != 0xe0) || ((nb & 0xc0) != 0x80) || ((nnb & 0xc0) != 0x80)) {
throwDataFormatException(
"invalid marker bits for triple byte char", utf8.position() - 3);
}
if (c < '\u0800') {
throwDataFormatException(
"encountered triple byte char that should have been fewer bytes",
utf8.position() - 3);
}
}
}
} catch (ArrayIndexOutOfBoundsException e) {
throwDataFormatException("unexpected end", utf8.position());
}
}
}
/**
* Convert the given sequence of (pseudo-)utf8 formatted bytes into a String.
*
* <p>The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8,
* and ALLOW_PSEUDO_UTF8 flags.
*
* @param utf8 (pseudo-)utf8 byte array
* @throws UTFDataFormatException if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8
* @return unicode string
*/
public static String fromUTF8(ByteBuffer utf8) throws UTFDataFormatException {
UTF8CharacterVisitor visitor = new ByteBufferStringEncoderVisitor(utf8.remaining());
visitUTF8(utf8, visitor);
return visitor.toString();
}
/**
* Convert the given sequence of (pseudo-)utf8 formatted bytes into a String.
*
* <p>The acceptable input formats are controlled by the STRICTLY_CHECK_FORMAT, ALLOW_NORMAL_UTF8,
* and ALLOW_PSEUDO_UTF8 flags.
*
* @param utf8 (pseudo-)utf8 byte array
* @throws UTFDataFormatException if the (pseudo-)utf8 byte array is not valid (pseudo-)utf8
* @return unicode string
*/
public static String fromUTF8(byte[] utf8) throws UTFDataFormatException {
UTF8CharacterVisitor visitor = new ByteArrayStringEncoderVisitor(utf8.length);
visitUTF8(utf8, visitor);
return visitor.toString();
}