StAXParser.java 文件源码

/**
 * Method for parsing orders XML.
 * @param is input stream for parsing.
 * @return SortedMap of OrderBook's mapping key name.
 * @throws FileNotFoundException if there is no such file.
 * @throws XMLStreamException The base exception for unexpected processing errors.  This Exception
 * class is used to report well-formedness errors as well as unexpected
 * processing conditions.
 */
public SortedMap<String, OrderBook> parse(InputStream is) throws FileNotFoundException, XMLStreamException {
    SortedMap<String, OrderBook> orders = new TreeMap<>(String::compareTo);
    XMLInputFactory factory = XMLInputFactory.newInstance();
    XMLStreamReader reader = factory.createXMLStreamReader(is);
    OrderBook orderBook;
    String book;
    reader.next();
    while (reader.hasNext()) {
        if (reader.next() == XMLStreamConstants.START_ELEMENT) {
            if (reader.isStartElement()) {
                book = reader.getAttributeValue(null, "book");
                if ("AddOrder".equals(reader.getLocalName())) {
                    if (!orders.containsKey(book)) {
                        orderBook = new OrderBook(book);
                        orders.put(book, orderBook);
                    } else {
                        orderBook = orders.get(book);
                    }
                    orderBook.addOrder(OrderBook.OPERATION.valueOf(reader.getAttributeValue(null, "operation")),
                            Integer.parseInt(reader.getAttributeValue(null, "orderId")),
                            Integer.parseInt(reader.getAttributeValue(null, "volume")),
                            Float.parseFloat(reader.getAttributeValue(null, "price")));
                } else {
                    orders.get(book).delOrder(Integer.parseInt(reader.getAttributeValue(null, "orderId")));
                }
            }
        }
    }
    return orders;
}