ntriplesparser.java

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		else if (c != '.') {
			_throwParseException("Expected '.', found: " + (char)c);
		}

		c = _skipLine(c);

		_statementHandler.handleStatement(_subject, _predicate, _object);

		_subject = null;
		_predicate = null;
		_object = null;

		return c;
	}

	private int _parseSubject(int c)
		throws IOException, ParseException
	{
		StringBuffer buf = new StringBuffer(100);

		// subject is either an uriref (<foo://bar>) or a nodeID (_:node1)
		if (c == '<') {
			// subject is an uriref
			c = _parseUriRef(c, buf);
			_subject = _createURI(buf.toString());
		}
		else if (c == '_') {
			// subject is a bNode
			c = _parseNodeID(c, buf);
			_subject = _createBNode(buf.toString());
		}
		else if (c == -1) {
			_throwEOFException();
		}
		else {
			_throwParseException("Expected '<' or '_', found: " + (char)c);
		}

		return c;
	}

	private int _parsePredicate(int c)
		throws IOException, ParseException
	{
		StringBuffer buf = new StringBuffer(100);

		// predicate must be an uriref (<foo://bar>)
		if (c == '<') {
			// predicate is an uriref
			c = _parseUriRef(c, buf);
			_predicate = _createURI(buf.toString());
		}
		else if (c == -1) {
			_throwEOFException();
		}
		else {
			_throwParseException("Expected '<', found: " + (char)c);
		}

		return c;
	}

	private int _parseObject(int c)
		throws IOException, ParseException
	{
		StringBuffer buf = new StringBuffer(100);

		// object is either an uriref (<foo://bar>), a nodeID (_:node1) or a
		// literal ("foo"-en or "1"^^<xsd:integer>).
		if (c == '<') {
			// object is an uriref
			c = _parseUriRef(c, buf);
			_object = _createURI(buf.toString());
		}
		else if (c == '_') {
			// object is a bNode
			c = _parseNodeID(c, buf);
			_object = _createBNode(buf.toString());
		}
		else if (c == '"') {
			// object is a literal
			StringBuffer lang = new StringBuffer(8);
			StringBuffer datatype = new StringBuffer(40);
			c = _parseLiteral(c, buf, lang, datatype);
			_object = _createLiteral(buf.toString(), lang.toString(), datatype.toString());
		}
		else if (c == -1) {
			_throwEOFException();
		}
		else {
			_throwParseException("Expected '<', '_' or '\"', found: " + (char)c);
		}

		return c;
	}

	private int _parseUriRef(int c, StringBuffer uriRef)
		throws IOException, ParseException
	{
		// Supplied char is '<', ignore it.

		// Read up to the next '>' character
		c = _reader.read();
		while (c != '>') {
			if (c == -1) {
				_throwEOFException();
			}
			uriRef.append( (char)c );
			c = _reader.read();
		}

		// c == '>', read next char
		c = _reader.read();

		return c;
	}

	private int _parseNodeID(int c, StringBuffer name)
		throws IOException, ParseException
	{
		// Supplied char is '_', ignore it.

		c = _reader.read();
		if (c == -1) {
			_throwEOFException();
		}
		else if (c != ':') {
			_throwParseException("Expected ':', found: " + (char)c);
		}

		c = _reader.read();
		if (c == -1) {
			_throwEOFException();
		}
		else if (!NTriplesUtil.isLetter(c)) {
			_throwParseException("Expected a letter, found: " + (char)c);
		}
		name.append( (char)c );

		// Read all following letter and numbers, they are part of the name
		c = _reader.read();
		while (c != -1 && NTriplesUtil.isLetterOrNumber(c)) {
			name.append( (char)c );
			c = _reader.read();
		}

		return c;
	}

	private int _parseLiteral(
		int c, StringBuffer value, StringBuffer lang, StringBuffer datatype)
		throws IOException, ParseException
	{
		// Supplied char is '"', ignore it.

		// Read up to the next '"' character
		c = _reader.read();
		while (c != '"') {
			if (c == -1) {
				_throwEOFException();
			}
			value.append( (char)c );

			if (c == '\\') {
				// This escapes the next character, which might be a double quote
				c = _reader.read();
				if (c == -1) {
					_throwEOFException();
				}
				value.append( (char)c );
			}

			c = _reader.read();
		}

		// c == '"', read next char
		c = _reader.read();

		if (c == '@') {
			// Read language
			c = _reader.read();
			while (c != -1 && c != '.' && c != '^' && c != ' ' && c != '\t') {
				lang.append( (char)c );
				c = _reader.read();
			}
		}
		else if (c == '^') {
			// Read datatype
			c = _reader.read();

			// c should be another '^'
			if (c == -1) {
				_throwEOFException();
			}
			else if (c != '^') {
				_throwParseException("Expected '^', found: " + (char)c);
			}

			c = _reader.read();

			// c should be a '<'
			if (c == -1) {
				_throwEOFException();
			}
			else if (c != '<') {
				_throwParseException("Expected '<', found: " + (char)c);
			}

			c = _parseUriRef(c, datatype);
		}

		return c;
	}

	private URI _createURI(String uri)
		throws ParseException
	{
		try {
			uri = NTriplesUtil.unescapeString(uri);
		}
		catch (IllegalArgumentException e) {
			_throwParseException(e.getMessage());
		}

		try {
			return _valFactory.createURI(uri);
		}
		catch (Exception e) {
			_throwParseException(e);
			return null;
		}
	}

	private BNode _createBNode(String nodeID)
		throws ParseException
	{
		// Maybe the node ID has been used before:
		BNode result = (BNode)_bNodeIdMap.get(nodeID);

		if (result == null) {
			// This is a new node ID, create a new BNode object for it
			try {
				if (_preserveBNodeIds) {
					result = _valFactory.createBNode(nodeID);
				}
				else {
					result = _valFactory.createBNode();
				}
			}
			catch (Exception e) {
				_throwParseException(e);
			}

			// Remember it, the nodeID might occur again.
			_bNodeIdMap.put(nodeID, result);
		}

		return result;
	}

	private Literal _createLiteral(String label, String lang, String datatype)
		throws ParseException
	{
		try {
			label = NTriplesUtil.unescapeString(label);
		}
		catch (IllegalArgumentException e) {
			_throwParseException(e.getMessage());
		}

		if (lang.length() == 0) {
			lang = null;
		}

		if (datatype.length() == 0) {
			datatype = null;
		}

		URI dtURI = null;
		if (datatype != null) {
			dtURI = _createURI(datatype);

			if (_datatypeHandling == DT_VERIFY) {
				if (!XmlDatatypeUtil.isValidValue(label, datatype)) {
					_throwParseException("'" + label + "' is not a valid value for datatype " + datatype);
				}
			}
			else if (_datatypeHandling == DT_NORMALIZE) {
				try {
					label = XmlDatatypeUtil.normalize(label, datatype);
				}
				catch (IllegalArgumentException e) {
					_throwParseException("'" + label + "' is not a valid value for datatype " + datatype + ": " + e.getMessage());
				}
			}
		}

		try {
			if (dtURI != null) {
				return _valFactory.createLiteral(label, dtURI);
			}
			else if (lang != null) {
				return _valFactory.createLiteral(label, lang);
			}
			else {
				return _valFactory.createLiteral(label);
			}
		}
		catch (Exception e) {
			_throwParseException(e);
			return null;
		}
	}

	private void _throwParseException(String msg)
		throws ParseException
	{
		if (_errListener != null) {
			_errListener.fatalError(msg, _lineNo, -1);
		}

		throw new ParseException(msg, _lineNo, -1);
	}

	private void _throwParseException(Exception e)
		throws ParseException
	{
		if (e instanceof ParseException) {
			throw (ParseException)e;
		}
		else {
			if (_errListener != null) {
				_errListener.fatalError(e.getMessage(), _lineNo, -1);
			}

			throw new ParseException(e, _lineNo, -1);
		}
	}

	private void _throwEOFException()
		throws ParseException
	{
		_throwParseException("Unexpected end of file");
	}
}